Double Whammy: Asteroids Delivered One-Two Punch
By Robert Roy Britt
Senior Science Writer
posted: 07:00 am ET
26 July 2004

A pair of 35-million-year-old craters on Earth thought to have been carved by comets now appears to be the result of a broken asteroid that generated a slowly delivered shower of debris over millions of years.

One crater is in Chesapeake Bay off the Maryland coast. The other, called the Popigai crater, is in north-central Siberia. Estimates of their age suggest they were created a mere 10,000 years apart.

Scientists had thought a comet shower of some sort had left the two scars.

Asteroid go platinum

A new study of the Popigai crater finds an abundance of elements from the platinum group, a signature common to asteroids and not thought to suggest comets, which hold more water ice and lower concentrations of metals.

The timing of the two impacts suggests the Chesapeake crater may have been caused by the same parent asteroid, which in this scenario broke apart in space and showered the Earth with many fragments large and small, explained geology professor Phillipe Claeys of Vrije Universiteit Brussel in Belgium.

"The chance to have over a short time scale the impact of an asteroid and that of a comet occurring together is unlikely -- not impossible, but very unlikely," Claeys told SPACE.com. He said objects up to 3 miles wide (5 kilometers) -- big enough to form the craters in question -- hit Earth once every 25 to 30 million years.

Other studies have found that when asteroids collide and break apart, their fragments can move from the asteroid belt between Mars and Jupiter to reach Earth's vicinity over long time periods. Earth can then be hit by successive pieces on its continual trip around the Sun.

Slow storm

Other evidence reveals extra space dust particles, perhaps the product of the asteroid's breakup in space, falling on Earth for 2.5-million-years around the same time as the two large impacts, Claeys said.

That suggests a slow rain of debris created increased rates of dramatic fireballs in the sky and possibly other large impacts. The drama might have spanned at least 10,000 years, he said, and other than the Chesapeake and Popigai craters, there would be little evidence today.

The asteroid that broke up to produce the asteroid shower "was much bigger" and "should have produced many more fragments than the two that came on an Earth collision course," Claeys said. "The Earth is two-thirds water, and we know little about craters in the deep ocean, but perhaps there were also one or two other projectiles that fell in the ocean during the period."

The uptick in activity would not have been noticeable over the course of the typical human lifetime.

The study, detailed Friday in the journal Science, was led by Roald Tagle of the Museum fuer Naturkunde in Berlin. The researchers plan to look for similar hard evidence that an asteroid built Chesapeake Bay.

This article is part of SPACE.com's weekly Mystery Monday series.

Sunspot Grows to 20 Times Size of Earth
By Robert Roy Britt
Senior Science Writer
posted: 05:10 pm ET
23 July 2004

A sunspot group aimed squarely at Earth has grown to 20 times the size of our planet and has the potential to unleash a major solar storm.

The amorphous mix of spots, together called Number 652, has been rotating across the Sun and growing for several days. On Friday, it sat at the center of the solar disk.

Sunspots are areas of intense magnetic energy, cooler and darker than the surrounding surface of the thermonuclear furnace. Sometimes the magnetic fields let loose and huge amounts of radiation and charged particles are hurled into space.

The Sun's last bout of intense storminess occurred last fall, when a string of 10 major flares over two weeks knocked out satellites, damaged others, and forced the FAA to reroute airlines away from exposed polar routes.

No one can say if this sunspot group will let loose with a major storm, but it has the characteristics of a potentially big event.

"The implications of this spot have scientists on the edge of their seats," NASA said in a statement Friday. "If the active region generates coronal mass ejections (CMEs), massive explosions with a potential force of a billion megaton bombs, it will be a fairly direct hit to Earth and its satellites and power grids."

The Sun is now in a generally quiet period of a well-known 11-year cycle of activity. But sunspots and flares can occur at any time. Scientists do not fully understand why the spots appear or how they erupt.

The sunspot is clearly visible from Earth without a telescope. But don't look at the Sun without a proper, safe filter or other viewing technique, or permanent eye damage can result.

I'll be glued to the TV set all week, starting tonight, awaiting the "Kerry Doctrine" of pre-emption - where we go out and vaporize all those space rocks, especially in the Asteroid Belt, before they can hit the earth! ;-)

Stitches, it's the little guys (100'-300' diameter city killers) that will escape detection. Like the one that exploded over Siberia in 1908. Kerry will have enough mess on his plate to deal with. vgkg

Natural Sunblock: Sun Dims in Strange Ways
By Robert Roy Britt
Senior Science Writer
posted: 07:14 am ET
02 August 2004

When Venus crossed the Sun June 8, showing up as a clear black dot to the delight of millions of skywatchers around the world, astronomers noted something less obvious: The amount of sunlight reaching Earth dipped by 0.1 percent for a few hours.

The result was not a surprise, but since Venus hadn't transited the Sun in more than a century, the effect had never been measured.

The drop in sunlight was similar to what happens when a large sunspot crosses the solar surface. But these forms of natural sunblock don't behave as you might expect, as witnessed by folks who froze their tails off a few hundred years ago across much of the Northern Hemisphere.

Two types of transits

Sunspots are cool, dimmer regions of the solar surface, packed with pent-up magnetic energy that sometimes unleash storms of X-rays and superheated gas. When they transit the face of the Sun, they are often visible without magnification to skywatchers using safe viewing techniques (looking directly at the Sun can cause permanent eye damage).

The planets Venus and Mercury, both orbiting inside Earth's path, also transit the Sun.

Sunlight reaching Earth is monitored by NASA's Solar Radiation and Climate Experiment (SORCE) satellite. The Venus transit proved to be a good test of instrument sensitivity.

"Because of its distance from Earth, Venus appeared to be about the size of a sunspot" on June 8, said Gary Rottman, SORCE Principal Investigator and a scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder.

Rottman and colleagues saw greater reductions in the Sun's energy coming Earthward during a stretch of intense solar activity last October, when several huge sunspots generated a record-breaking string of solar flares. At one point, sunlight dimmed 0.3 percent for about four days, due mostly to three large sunspot groups.

"This is an unprecedented large decrease in the amount of sunlight," Rottman said, and it is comparable to the decrease that scientists estimate occurred from roughly 1645 to 1715. During a broader period, from the 1400s to the 1700s, Europe and North America were plunged into what came to be called the Little Ice Age.

Dearth of sunspots

Scientists could not measure solar radiation back then. But sunspots were recorded by several astronomers, and Rottman and others believe there is a correlation between the climate of the time and the lack of sunspots.

"For a period of about 50 years, there were almost no sunspots," Rottman said in a telephone interview. "The total amount of radiation was, we assume, about three-tenths of 1 percent less" than in normal periods of solar activity.

If you've been paying attention, that might sound backward. Rottman's team measured a decrease in sunlight when Venus transited the Sun, and similar decreases are recorded when sunspots are present.

So why would there have been less radiation in the late 1600s when there were very few sunspots? Rottman explains:

Sunspots indicate greater solar activity in general. While they do dampen sunlight while on the face of the Sun, they are surrounded by intensely bright regions called "faculae" or "plage." When sunspots are on the limb of the Sun -- just rotating onto or off of the face -- the plage are prominent from our vantagepoint, creating a significant increase in radiation that far outweighs the dip of radiation caused by the rest of the sunspot's transit.

Seen on a graph, total visible and infrared radiation increases just before a sunspot appears, dips slightly for several days as it crosses the surface, then increases again as it disappears.

A lack of sunspots indicates inactivity in the Sun, and less radiation overall.

Still a mystery

The reduced solar activity of the 1600s and 1700s is called the Maunder minimum, after the solar astronomer Edward Walter Maunder, who during the 1800s investigated the historical sunspot records.

Nobody knows for sure why it occurred or whether it will happen again anytime soon. In fact, the whole concept remains controversial, because it's not clear how well astronomers were counting sunspots during the Maunder minimum. And the exact tie to climate is not understood. Most tend to agree, however, that there was a distinct lack of solar activity.

"Something very different was happening during the 17th Century, and it produced a much more permanent change in the Sun's energy output at that time," Rottman said.

Newfound Comet Set for Winter Display

By Joe Rao
SPACE.com Night Sky Columnist
posted: September 17, 2004
06:30 am ET ET

Donald Machholz of Colfax, California, an optician who has been interested in astronomy since age eight, discovered nine comet from 1978 through 1994. He has since spent 1,457 hours scanning the skies for other comets, without any luck.

But his luck changed on the morning of Aug. 27, when he swept up his tenth comet.

Machholz's latest discovery could become the third fourth this year to excite backyard astronomers.

After a treat of three comets in the spring -- NEAT, LINEAR and Bradfield -- the first indications suggest Machholz's discovery will become easily visible in binoculars and small telescopes this winter and possibly to the unaided eye.

Comets brightness is notoriously difficult to predict, however, and it is too early to know whether this one will put on a memorable show.

The discovery

When Machholz first picked up the comet – officially designated c/2004 Q2 – it was a fuzzy 11th-magnitude object in the constellation Eridanus and drifting slowly southeast in the direction of the constellation Lepus. On this astronomer scale, larger numbers represent dimmer objects. Under the darkest skies, the typical observer can spot with the unaided eye objects of magnitude 6.5 and brighter.

Machholz spotted the comet through the 30X eyepiece of his 6-inch f/8 Criterion Dynascope Newtonian reflector; a vintage telescope that was a mainstay among amateur astronomers during the 1960s and 70’s. Machholz had purchased his back in 1968. Several hours later, Australian observers Gordon Garradd and Robert McNaught confirmed the discovery, capturing the comet in photographs using telescopes from Siding Spring Mountain.

These CCD ("Charged Coupled Devices") images also showed a short, faint tail.

From 38 observations over a four-day period, Brian Marsden at the Minor Planet Center in Cambridge, Mass. calculated an orbit for the new Comet Machholz. It is on its way toward the vicinity of the Earth and the Sun, and during October and November, its projected path will appear to describe a small loop taking it into the constellations Lepus, Columba and Caelum. Since it will still be relatively far from both the Sun and Earth, its apparent motion -- in relation to the stars from night to night -- will be quite slow.

At the beginning of December it will return to Eridanus, at which point the comet’s motion across the sky will abruptly turn northward and rapidly increase, making the comet well placed for Northern Hemisphere observers by the last week of December.

How bright?

According to Marsden's calculations, Comet Machholz could become as bright as fourth magnitude, and possibly hovering around at this brightness for about a month beginning right after Christmas. During this interval, the comet will move north of the celestial equator, tracking from southern Taurus on up into the constellation Perseus.

Fourth magnitude means that the comet should at be at least dimly visible to the naked eye in dark skies, though better seen in binoculars or telescopes. Urban skywatchers would not be able to see it without optical aids.

That kind of brightness would still make Machholz a very fine comet from the viewpoint of an amateur astronomer, especially in early January, when it will be approaching the Earth and will be well placed for viewing -- high in a dark sky. Given current information, it doesn’t appear that this comet will become the kind of spectacle that Comet Hale-Bopp was in grabbing the public’s attention.

Hard to predict

And although the script is still being written for this comet's winter performance, Machholz advised that comets are notoriously bad actors. As an example, the first brightness estimates for Comet NEAT had it possibly becoming as bright as first magnitude -- easily visible even from cities. Ultimately it became only as bright as third magnitude at best.

Comet Machholz could brighten up and give us a real surprise. Comets have surprised on the bright side before. Yet few celestial events have greater false-alarm potential than these interplanetary vagabonds.

The comet is predicted to come closest to Earth on the night of Jan. 5-6, 2005, when it will be just 32 million miles (51 million kilometers) away. On the evening of Jan. 7, it will conveniently pass just a couple of degrees to the west of the famous Pleiades star cluster.

Comet Machholz will reach perihelion -- its point closest to the Sun -- on Jan. 24, when it will be just under 112 million miles (179 million kilometers) from that blazing furnace. The comet will be more-or-less opposite the Sun all during this "flyby", and thus should be easily visible in a dark sky from Earth.
end

I like to think that (and I hate this saying), "If we can put a man on the moon, then we can....", and we can drill a hole in the earth, extract a million-year old product and refine it, and then basically turn it into several products that not only propel, at great and safe speeds, multi-ton vehicles AND give us light, heat, and cold beer, that we can do the same with other elements. So, when I saw the article from Harrison Schmitt, I figured it was something worthy of asking you.

Guess I'll just take my puny 6" Meade Dobsonian telescope outside, pop open a few dinosaur-powered and cooled beers (since old Ballard Energy won't cough up the residential fuel-cell generators AGAIN!!!), and watch the stars, knowing that people are thinking, but not pushing the energy envelope.

Thanks again for the response.

Space Weather News for Sept. 23, 2004
http://spaceweather.com

ASTEROID FLYBY: Asteroid 4179 Toutatis is flying past Earth this week. The weirdly tumbling space rock is close enough (4 lunar distances) and bright enough (9th magnitude) to see through backyard telescopes. For the next few days it will scoot through the constellation Capricornus where amateur astronomers worldwide can find it. By Sept. 29th, when Toutatis is closest to Earth, it will be visible mainly from the southern hemisphere.
Observers there can see it passing not far from the bright star Alpha Centauri. Follow the links at spaceweather.com to sky maps and detailed ephemerides.

Toutatis is officially listed as a Potentially Hazardous Asteroid (PHA). If an asteroid like Toutatis were to impact the earth, the resultant explosion will be equivalent to that of one million megatons of TNT.

Discovered in 1989 by Christian Pollas, Toutatis is known for its unusual behaviour, its undefined shape, spin and unfixed axis.

The peanut shell, double shaped asteroid will be visible from the Southern Hemisphere and South Indian states, Sri Lanka, Australia, New Zealand, southern African countries and South America.

The movement of the asteroid can be observed through a telescope of six inches or higher aperture from September 21 to 29. It will move in the Microscopium constellation on September 25, in Indus on 26, and in the Pavo constellation on the 29th. Although it is currently at the 11th magnitude, the predicted brightness is at 9th magnitude on September 29.

Toutatis is 4.6km long and 2.4km wide. It is approaching us at the speed of 35,000 km per hour, which is fairly fast as compared to other asteroids of similar size.

Next on NOVA: "Origins"

http://www.pbs.org/nova/origins/

Broadcast: September 28 & 29, 2004 from 8-10 p.m.
(NOVA airs Tuesdays on PBS at 8 p.m. Check your local listings as dates and times may vary.)

Has the universe always existed? How did it become a place that could harbor life? Are we alone, or are there alien worlds waiting to be discovered? NOVA presents some startling new answers in "Origins," a groundbreaking four-part miniseries. Hosted by Dr. Neil deGrasse Tyson, astrophysicist and Director of the Hayden Planetarium at the American Museum of Natural History, the miniseries investigates new clues from the frontiers of science. Over two nights, Tyson guides viewers on a cosmic journey to the beginning of time and to the depths of space, searching for life's first stirrings and its traces on other worlds.

Here's what you'll find on the companion Web site:

Inquiry, Interviews, and More

Life's Little Essential
Everybody knows that liquid water is necessary for life. But just
why exactly?

A Conversation With Neil deGrasse Tyson
Hear from the series host on the hottest discoveries in origins
research, his advice for budding scientists, and more.

How did Life Begin?
Harvard's Andrew Knoll discusses the deeply mysterious jump long
ago from non-living to living.

Does Mars Have Life?
NASA's Christopher McKay thinks the red planet once had living
things and maybe, just maybe, still does.

Who Needs Galaxies?
Astronomer Sandra Faber explains how galaxies brew the
ingredients for life.

Are We Alone?
Paleontologist Peter Ward says that as intelligent creatures, we
humans are probably not alone in the universe, just very lonely.

Interactives and Slide Shows

Do Aliens Exist in the Milky Way?
In this interactive poll, explore a series of arguments for and
against, then vote online. (Results to date: 79% yes, 14% no,
and 7% undecided).

The Drake Equation
Try your hand at calculating how many intelligent, communicating
civilizations might be in our galaxy.

Decoding Cosmic Spectra
Play astronomer and analyze the spectral fingerprints of a
planet, star, galaxy, and nebula.

The Pillars of Creation
Assemble the famous image of the Eagle Nebula from raw data
beamed down from the Hubble Space Telescope.

The Origins Game
Where are scientists making the great discoveries in origins
research? Check out our world map.

History of the Universe
This interactive time line chronicles the evolution of the
universe from the big bang to 10 to the 100 years from now.

A Brief History of Life
Review the grand march of organisms from over three billion
years ago to the present.

ET Gallery
Sci-fi films and T.V. shows reveal how limited our imagination
is when it comes to alien life.

Also, watch a video preview of the program, find out when to join a washingtonpost.com chat with astrophysicist and series host Neil deGrasse Tyson, browse Links & Books, get a recipe for "Cosmic Soup," and more.

http://www.pbs.org/nova/origins/

_____________________________________________________________________

Life, the Universe and Everything: How Astronomy Addresses the Big Questions

By Seth Shostak
The SETI Institute
posted: 21 October, 2004
7:00 a.m. ET

There are some questions that have curdled the brains of hominids ever since they developed the power to ponder. Questions like "what is the nature of evil?" or "what caused the Cambrian explosion?" not to mention Freud’s famous stumper, "what does a woman want?"

There’s no doubt, however, that the query most universally posed is the big one: "what’s it all about?" What is the point of our existence, where ‘our’ refers not just to you, your kith, and your kin, but to Earth, the stars, and the entire ball of cosmic wax?

In the interests of mental equanimity, most of the time you’re going to sail this question to the dark basement of your mind. After all, you’ve got appointments to make and deadlines to meet. Not many of us can afford the luxury, nor withstand the frustration, of constantly asking ourselves "what’s the point?" It’s easier to defer that question either to theologians or to philosophers who, presumably, are paid a salary to think of such matters.

Could astronomy help us figure out the meaning of it all? Well, it can’t actually answer the question, but it can supply a context, much the way surrounding seas give context to the history of Britain.

So what does astronomy say? As recently as the dawn of the twentieth century, most people figured that the universe had been around forever, and always would be. We were just a piece of cosmic flotsam, adrift in an endless river. Then, only a single lifetime ago, Edwin Hubble showed that the universe is expanding – thinning out at a rate that adds 20 billion miles to the distance between your driveway and the nearby Virgo Cluster of galaxies every year. Indeed, as most learned readers will know, recent astronomical measurements show that this cosmic stretching is speeding up.

But never mind that. The important point is that an expanding universe, perforce, must have had a start – a beginning. This has a nice consonance with most religions, of course, which may explain why Hubble took less heat for his discovery than did Copernicus or Galileo.

The kicker, however, is what happens next. Our Sun, a relative newcomer to the Galaxy, will, like your least favorite uncle, go funny as it ages. In another five billion years or so, it will swell up, swallow a few inner planets, and boil away all that’s interesting on our world. Our descendants (presuming we have any) will relocate to a better neighborhood – bringing along photos and artifacts for future museum exhibits on "Earth: the Planet That Was."

They’ll be able to do this a few times before running out of steam. After all, most stars are older than the Sun, and the stellar population boom is definitely over. The Galaxy is graying (although the actual color change is to the red). The stars are going out. In about 100 billion years, the once-brightly spangled arms of the Galaxy will be riddled with Sun-sized carbon clinkers, black holes, and quiescent neutron stars – a hundred billion mute, stellar hulks.

The fun will be over, but the decay will go on. Chaotic encounters will eventually strip planets from the corpses of their erstwhile suns, and galaxies will slowly evaporate – spewing their dark and lifeless contents into the ever-expanding void. Even massive black holes will someday melt away, adding their mass to the inert and keenly cold fog that the universe will become.

The cosmos will be a deathly silent graveyard, cloaked in perpetual night.

As best we can deduce from measurement, this somber scenario will play out endlessly. There will be no reversal, no Big Crunch to start the cycle anew. The cosmos – dark, uninteresting and inactive – will simply continue to expand and thin.

So here’s the big picture: the universe begins with a 100 billion-year blip of activity, and then flatlines to endless paralysis. All our works – all the poetry, the science, the tenderness, and the rock-and-roll – all will be stilled and lost. The death of the universe is not just long – it’s eternal. The short, bright spurt at the beginning where we now find ourselves is not only insignificantly short in the cosmos’ history, it’s infinitely short.

There’s a short breath, a quick bump, and then a line of nothingness that stretches across the room, out the door, and down the street forever.

Given our seeming lack of importance, and the fact that there will be no legacy in this universe, it’s tempting to choose to live for the moment (like your cat). Maybe thinking about why we’re here is useless and no more than a temptation to madness. On the other hand, perhaps one day we’ll learn something that will change this bleak picture, either by dint of our own efforts, or possibly via wisdom sent to us by other, yet-to-be-discovered cosmic beings.

Freud said "anatomy is destiny." His subject was women, but it could have been the universe.

By Robert Roy Britt
Senior Science Writer
Space.com
posted: 26 October 2004
06:26 am ET

Newly discovered galactic highways cut across the Milky Way at odd angles, bringing stars through the neighborhood of our solar system.

The roads of rebels could be part of a galaxy-wide system of divergent stellar byways, researchers say.

The Sun and most other stars in our Milky Way orbit the galactic center on fairly routine, circular paths. So astronomers were surprised to find in a new survey that about 20 percent of the stars within 1,000 light-years of the Sun are moving on a bunch of offbeat trajectories.

The Sun is at "a crossroads of many streams," according to a research team that examined data on more than 100,000 stars gathered by the European Space Agency's Hipparcos satellite. The routes are mostly headed toward or away from the galactic center, like spokes on a wheel. Stars on each of the courses vary significantly in age and composition, suggesting they had different origins and haven't always been on their present paths.

"They resemble casual travel companions more than family members," said Benoit Famaey, Université Libre de Bruxelles, Belgium.

So what caused all the commotion?

Density waves

Famaey's team believes the stars have been gravitationally stirred by the spiral arms of the Milky Way. Each arm is packed with more stars and gas than the areas between the arms. These density waves, as astronomers call them, compress gas and force star formation. They can also deflect the motion of stars.

"If these stars are kicked by a spiral arm, they can be displaced thousands of light-years away from their birthplace," Famaey said.

While the setup might sound chaotic, there is little if any additional threat to our solar system. In principle, the newly realized star paths mean the chance of a collision or other interaction with the Sun is greater than was previously known, said Alain Jorissen, also of Université Libre.

"But in practice," Jorissen told SPACE.com, "average distances between stars are so large anyway that the chance of a close encounter remains quite small."

Eventually, most of the rebels will be straightened out. Over time, the disruptive effect of a spiral arm will vanish as a star moves away from the arm and the galaxy's collective gravity takes over.

"It is likely that the star will then find itself on a more conventional orbit," Jorissen said.

The next close call

The closest stars currently known are a trio that make up the Alpha Centauri system, which is 4.36 light-years away. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

Meanwhile, our next known close encounter with another star will occur 1.4 million years from now.

A star named Gliese 710, found by Hipparcos and reported in 1999, will pass within 1 light-year of the Sun. That puts it some 70,000 times the distance from Earth to the Sun, on the very fringes of our solar system where icy objects are thought to roam in what's known as the Oort Cloud. Such stellar close calls in the past are thought to have rerouted comets from the Oort Cloud toward the inner solar system, where some hit Earth.

Gliese 710 "does not seem to belong to one of our streams," Jorissen said.

To turn the Hipparcos data into a 3-D view of the solar neighborhood, the researchers added observations on each star's movement collected by a Swiss telescope at the Observatoire de Haute-Provence in France. A movie depicting the streams is available at space.com website.

The results are detailed this month in the European journal Astronomy & Astrophysics.

In essence...don't sweat 5 billion years down the way. Whoever made it had the answer then.

Sunspots have been more common in the past seven decades than at any time in the last 8,000 years, according to a new historic reconstruction of solar activity.

Many researchers have tried to link sunspot activity to climate change, but the new results cannot be used to explain global warming, according to the scientists who did the study.

Sunspots are areas of intense magnetic energy. They act like temporary caps on upwelling matter, and they are the sites of occasional ferocious eruptions of light and electrified gas. More sunspots generally means increased solar activity.

Sunspots have been studied directly for about four centuries, and these direct observations provide the most reliable historic record of solar activity. Previous studies have suggested cooler periods on Earth were related to long stretches with low sunspot counts. From the 1400s to the 1700s, for example, Europe and North America experienced a "Little Ice Age." For a period of about 50 years during that time, there were almost no sunspots.

But a firm connection between sunspot numbers and climate remains elusive, many scientists say.

Better record

The new study, led by Sami Solanki of the Max Planck Institute in Germany, employed a novel approach to pinning down sunspot activity going back 11,400 years:

Cosmic rays constantly bombard Earth's atmosphere. Chemical interactions create a fairly constant source of stuff called carbon-14, which falls to Earth and is absorbed and retained by trees. But charged particles hurled at Earth by active sunspots deflect cosmic rays. So when the Sun gets wild, trees record less carbon-14.

While trees don't typically live more than a few hundred years or perhaps a couple thousand, dead and buried trees, if preserved, carry a longer record, "as long as tree rings can be identified," said Manfred Schuessler, another Max Planck Institute researcher who worked on the study.

The study's finding: Sunspot activity has been more intense and lasted longer during the past 60 to 70 years than at anytime in more than eight millennia.

Sunspot activity is known to ebb and flow in two cycles lasting 11 and 88 years (activity is currently headed toward a short-term minimum). Astronomers think that longer cycles -- or at least long-term variations -- also occur. Scientists in other fields have shown that during the past 11,000 years, Earth's climate has had many dramatic shifts.

"Whether solar activity is a dominant influence in these [climate] changes is a subject of intense debate," says Paula Reimer, a researcher at Queen's University Belfast who wrote an analysis of the new study for Nature. Why? Because "the exact relationship of solar irradiance to sunspot number is still uncertain."

In general, studies indicate changes in solar output affect climate during periods lasting decades or centuries, "but this interpretation is controversial because it is not based on any understanding of the relevant physical processes," study member Schuessler told SPACE.com. Translation: Scientists have a lot to learn about the Sun-Earth connection.

Better understanding

The study's methods appear solid: "The models reproduce the observed record of sunspots extremely well, from almost no sunspots during the seventeenth century to the current high levels," Reimer said.

The research could eventually help scientists understand why the climate has changed in the past and allow for better predictions of future change.

"The reconstructed sunspot number will nonetheless provide a much-needed record of solar activity," Reimer said. "This can then be compared with palaeoclimate data sets to test theories of possible solar–climate connections, as well as enabling physicists to model long-term solar variability."

Whatever the result, change is likely to continue.

Solanki's team calculates that, based on history, the chances of sunspot activity remaining at the currently high levels for another 50 years is 8 percent. Odds are just 1 percent the solar exuberance will last through the end of this century

The Hubble Space Telescope captured a rare alignment of Jupiter's moons earlier this year in this picture, which was released today.

Three of Jupiter's largest moons -- Io, Ganymede, and Callisto -- cast dark shadows on Jupiter in this near-infrared image. In these mini-solar eclipses, the moons block the sunlight that otherwise reflects off Jupiter. Io's shadow is located just above center and to the left; Ganymede's on the planet's left edge; and Callisto's near the right edge.

Two of the moons are directly visible in the image. Io is the white circle in the center, and Ganymede is the blue circle at upper right. Callisto is out of the image and to the right.

The image was taken March 28, 2004.

Seeing three shadows on Jupiter happens only about once or twice a decade. Io, Ganymede, and Callisto orbit Jupiter at different rates, Hubble astronomers explained. Their shadows likewise cross Jupiter's face at different rates.

For example, the outermost moon Callisto orbits the slowest of the three satellites. Callisto's shadow moves across the planet once for every 20 shadow crossings of Io.

Add the crossing rate of Ganymede's shadow and the possibility of a triple eclipse becomes even more rare. Viewing the triple shadows in 2004 was even more special, because two of the moons were crossing Jupiter's face at the same time as the three shadows.

Jupiter and Venus are easily visible this week in the morning sky.

-- SPACE.com Staff

A star that exploded about nearly three million years ago left traces of debris on Earth and might have affected the course of human evolution, a new study suggests.

When particles from the explosion bombarded Earth's atmosphere over a long stretch of time, climate change could have forced early humans to fan out in search of food, the reasoning goes.

The evidence is in the form of extra doses of iron-60, a radioactive isotope of iron that normally occurs on Earth in lesser quantities. Researchers found the supernova debris in layers of soil dated to 2.8 million years ago, building a case they opened five years ago with less concrete data.

Visible in daylight

The star that exploded was several times more massive than our Sun.

"For a very short time this explosion released as much light as a whole galaxy," explained study leader Gunther Korschinek of the Technical University of Munich, in Germany. Much of the debris -- newly formed elements -- was absorbed by interstellar dust and gas. But some washed over our solar system.

The same research group found abundancies of iron-60 five years ago, but the new findings are at a different site 3,000 miles away and in layers that are more accurately dated. The results are detailed in the Oct. 22 issue of the journal Physical Review Letters.

According to an article at the online site of the British journal Nature, the discovery "represents an experimental triumph and a milestone in this field," said astrophysicist Brian Fields of the University of Illinois at Urbana-Champaign. Fields said the result marks the birth "supernova archaeology."

Scientists have estimated that somewhere between one and three stars go supernova in our galaxy every 100 years. One probably occurs near our solar system every five million to 10 million years, researchers estimate.

"Our finding shows now for the first time traces from a supernova close to the Earth," Korschinek said in an email interview. "It would have been so bright, that it was easy to see during daytime."

But not too close.

We're still here

The supernova lit up somewhere between 30 light-years and 300 light-years from Earth, the study concludes. The rough estimate is due to the fact that the star's exact mass isn't known, and the extent of iron-60 is also not fully known. There is one pretty solid clue that helps provide a minimum distance: Our ancestors survived and even thrived.

"We know if the star would have exploded too close, we could not talk by e-mail as I do now," he told SPACE.com.

Astronomers cannot accurately lay out the local effects of a supernova. But one can speculate.

Ernst Dorfi, of the University of Vienna, calculates the supernova in Korschinek's study would have generated an increase in cosmic radiation hitting Earth, probably of several percent over a few hundred thousand years.

Other scientists believe extra cosmic rays would fuel increased cloudiness and a drop in temperatures, though the idea needs further research, Korschinek says.

"Interestingly, a temperature drop at that time can be seen in geological records," Korschinek points out, adding that there are other theoretical explanations for the change. Whatever the cause, evolutionary theorists think the climate change of that time forced early humans to adapt, and to leave drying Africa in search of wetter climates.

"So, perhaps -- but not proven -- this supernova was one reason for our existence."

This article is part of SPACE.com's weekly Mystery Monday series

Spaceweather alert :
AURORA WATCH: A coronal mass ejection (CME) is heading for Earth. When it arrives, perhaps tonight, it could trigger a geomagnetic storm and auroras.

Sky watchers have already seen one spectacular display this week. An extreme geomagnetic storm on Nov. 7th and 8th sparked Northern Lights as far south as Oklahoma, Alabama and California in the United States.

It may not scare you to death, but this look at the Martian moon Phobos - or Fear - is one of the most detailed observations of the small satellite.

Phobos is the largest and innermost of Mars' two moons. The lumpy satellite is about 11 miles (18 kilometers) in diameter at its narrowest point and circles Mars once every eight hours.

This image was taken by the High Resolution Stereo Camera aboard the European Space Agency's (ESA) Mars Express spacecraft on Aug. 22, 2004, but released Nov. 11. It shows the Mars-facing side of Phobos.

Mars Express flew within 124 miles (200 kilometers) of Phobos to take this picture, which has a resolution of about 22 feet (7 meters) per pixel and is one of the highest-resolution views of the moon ever recorded. The scale at the upper right is applicable only to the center of the image due to geometric reasons.

-- SPACE.com Staff

Credit: ESA/DLR/FU Berlin/G. Neukum

A fabled tenth planet out beyond Neptune, often referred to as Planet X, hasn't been found despite years of searching. But astronomers involved in the hunt are beginning to speculate that something like Planet X will be discovered, along with Y and Z.

In fact, the entire alphabet may not suffice to denote the many worlds circling the Sun.

In an emerging new theoretical view of our corner of the galaxy, several worlds larger than Pluto -- a few perhaps as big as Mars -- lurk in the outskirts of the solar system. Some are so far away that it would take more than a year, traveling at the speed of light, to reach them.

Wrapping up one search

For years, astronomers have been scouring the Kuiper Belt, a region past Neptune that's loaded with comet-like objects. The Kuiper Belt extends out to some 5 billion miles (8 billion kilometers) from the Sun. That's a little more than 50 times the distance between Earth and the Sun, or 50 astronomical units (AU).

Since 1992, more than 800 Kuiper Belt Objects (KBOs) have been found. A handful look to be roughly half the size of Pluto. Until recently, the larger KBOs had fueled speculation that one or more Pluto-sized bodies would eventually be found.

"Given that our survey has covered almost the entire region of the Kuiper Belt, I'm willing to bet these days that nothing larger than Pluto will be found in the Kuiper Belt," says Caltech astronomer Mike Brown.

As hope fades, a study released earlier this month shows that some KBOs are smaller than had been assumed.

The size of a distant object is often based on an estimate of its reflectivity, a measure called albedo. For years astronomers had assumed KBOs were pretty dark, reflecting just 4 percent of the sunlight that hit them.

University of Arizona astronomer John Stansberry used NASA's Spitzer Space Telescope to obtain actual albedos for some of these icy objects.

"Our results have albedos ranging from 6 percent to 18 percent for the eight objects I've analyzed," Stansberry said. If a KBO is brighter than thought, then less surface area is required to reflect the amount of sunlight that was measured -- so the object's size must be revised downward.

One object, catalogued as 2002 AW197, was thought to be two-thirds the diameter of Pluto. Stansberry has now shrunk that estimate to about one-third.

Looking into a new realm

Some of the larger objects out there have not shrunk, however, because their actual albedos were already fairly well known. One of these is way, way out there, and it is seen as a missing link to the space beyond the Kuiper Belt.

Last November, Mike Brown's team found a world at least half as large as Pluto. They named it Sedna, after the Inuit sea goddess. Sedna's elongated orbit is outside the Kuiper Belt, ranging from 76 to 1,000 AU.

Sedna was found only because it is currently near the innermost stretch of its travels.

Well past Sedna is another reservoir of material left over from the formation of the solar system, theorists believe. The Oort Cloud is a hypothesized sphere of frozen objects thought to start at about 10,000 AU and extend to 100,000 AU, or 1.5 light-years from the Sun.

Nobody expected to find an object like Sedna in the largely empty space between the Kuiper Belt and the Oort Cloud. Theorists are now scrambling to explain Sedna's presence and what it means to the composition of the outer solar system.

"Sedna could be a member of a substantial population of bodies trapped between the Kuiper Belt and Oort Cloud," says the University of Hawaii's David Jewitt, who made the first accurate estimate of a KBO albedo in 2001.

Brown, who now bets against finding Planet X in the Kuiper Belt, thinks his group's discovery of Sedna portends an even more compelling scenario.

"I'd also be willing to bet that there are many objects larger than Pluto out in the region of space where Sedna lives," Brown said last week. Out to about 1,000 AU, he speculates that there could be 10 or 20 Pluto-sized objects, "and a handful of larger things, too." Some of these suspected worlds could be as big as Mercury or even Mars, he said.

I asked Brown if there might be worlds larger than Pluto clear out at the edge of the Oort Cloud, 1.5 light-years away and nearly half the distance to the Alpha Centauri star system.

"Absolutely," he said. "Probably even likely."

Waiting on technology

New telescopes will be needed to connect the dots of the outer solar system.

"Pluto-sized planets in distant near-circular orbits are beyond the reach of current searches," said Lowell Observatory astronomer Bob Millis, who leads a team that has found more than 400 KBOs. "Future searches tuned to more distant objects and using large telescopes … can begin to probe this region."

And while Mike Brown has his mental sights set beyond Sedna, Millis thinks there could still be a surprise lurking in the Kuiper Belt.

"It is certainly possible that one or more objects as large as Pluto remain to be found inside about 70 AU," Millis told me. "No searches performed to date are complete in this region," although he added that the survey by Brown and his colleagues, Chad Trujillo and David Rabinowitz, "has substantially reduced the likelihood" that such objects exist.

"Beyond about 70 AU," Millis said, "it is anybody's guess."

The location and orbit of Sedna is shown in relation to asteroids and Kuiper Belt Objects, and the hypothesized Oort Cloud of distant objects orbiting the Sun.
Credit: NASA/JPL-Caltech/R. Hurt

intereresting, still here!?

Now back to the newz...

Seems that astronomers are pleased with the latest supporting evidence which shows that planetary formation around stars is probably the norm :

Missing Link Spotted in Planet Formation
By Robert Roy Britt
Senior Science Writer
posted: 09 December 2004
02:09 pm ET

For several years scientists have been detecting planets around mature stars and, separately, imaging dust disks around younger stars. A strong theory has developed that planets form from these disks of material that are leftovers of the star formation process.

In other investigations, lumpy objects in young star systems have been seen, and researchers figure they're planets-in-the-making.

However there has been a glaring gap in the observations: Mature stars harboring both planets and disks have remained elusive, perhaps simply because the disks have thinned out to almost imperceptible levels.

New observations announced today begin to fill in the missing link.

NASA's Spitzer Space Telescope has detected dust disks around mature, Sun-like stars known to have planets. The dust is in the outlying reaches of each system and is presumed to result from collisions between objects, as occurs in our own solar system's Kuiper Belt, out beyond Neptune.

The half-dozen systems Spitzer analyzed contain gas giant planets. Rocky, Earth-sized planets might exist in them, but technology cannot find them now.
This animation shows the evolution of a planet-forming disk around a star. Initially, the young disk is bright and thick with dust, providing raw materials for building planets. In the first 10 million years or so, gaps appear within the disk as newborn planets coalesce out of the dust, clearing out a path. Credit: NASA/JPL.

The findings suggest theories of planet formation, including here in our solar system, are on track. It goes like this: A star is born amid a cloud of gas and dust. Leftovers swirl into a relatively flat disk that orbits the rotating star. Dust and chemicals collects and build rocky and icy objects, which collide. Some stick to make comets, asteroids and planets. Other collisions later on continue to produce dust -- which Spitzer detected.

A visible-light image (left)of a debris disk around the red dwarf star AU Microscopii and a false-color view (right) of a planetary debris disk encircling the star HD 107146, a yellow dwarf star very similar to our Sun, though it is much younger (between 30 and 250 million years old, compared to the almost 5 billion years age of the Sun).

The new results "fit into theoretical picture that we've built up about how stars and planetary system form," said Charles Beichman of NASA's Jet Propulsion Laboratory and lead author of the study.

"Spitzer has established the first direct link between planets and disks," Beichman said. "Now, we can study the relationship between the two."

Separate new observations by the Hubble Space Telescope reveal significant dust disks around a young star, one between 50 million and 250 million years old. Importantly, the star is similar to our Sun.

"The new Hubble image gives us the best look so far at reflected light from a disc around a star the mass of the Sun," said Hubble study leader David Ardila of the Johns Hopkins University. "Basically, it shows one of the possible pasts of our own solar system."

Both results were presented Thursday afternoon in a NASA teleconference with reporters.

Alycia Weinberger, an astronomer at the Carnegie Institution of Washington, suggests the dust around a star is like bricks at a construction site. Previous observations had revealed the bricks, she said, and other observations had shown the completed houses, but the two hadn't been found at the same site.

The new observations close the loop. They show us both the planets and the disks," said Weinberger.

By Leonard David
Senior Space Writer
posted: 14 December, 2004
7:00 a.m. ET

BOULDER, COLORADO -- Think of it as some sort of extraterrestrial axiom: Look for places on a celestial body where the Sun doesn’t shine.

NASA planners are now orchestrating America’s return to the Moon, with many experts hoping to hang their space helmet on the likelihood that ice is stored within permanently shadowed craters at the lunar poles.

Just one look is all it takes to see that the Moon has some natural "beauty marks"-- a landscape peppered by meteorites, micrometeorites and comets.

Most of these impactors showered water ice on the Moon. Any of that ice surviving those cosmic crashes would be strewn across the lunar landscape and rapidly vaporize. But some of that ice -- even down to individual molecules – could have wound up trapped inside supercold, permanently shadowed lunar craters.

Such an ice resource is considered invaluable if processed to create life-sustaining oxygen and water, even transformed into rocket fuel for propelling spacecraft beyond the Moon. However, whether or not this material – spotted by lunar orbiters of years past -- is actually water ice or hydrogen is open to question.

If, indeed, appreciable near-surface water ice is resident in polar "cold traps" on the Moon, it is both a storehouse of scientific knowledge as well as a resource bonanza.

Marching orders

Earlier this year, U.S. President George W. Bush spelled out a strategy for space exploration beyond low Earth orbit. For the Moon the White House marching orders to NASA were:

Undertake lunar exploration activities to enable sustained human and robotic exploration of Mars and more distant destinations in the solar system.
Starting no later than 2008, initiate a series of robotic missions to the Moon to prepare for and support future human exploration activities.
Conduct the first extended human expedition to the lunar surface as early as 2015, but no later than the year 2020.
Use lunar exploration activities to further science, and to develop and test new approaches, technologies, and systems, including use of lunar and other space resources, to support sustained human space exploration to Mars and other destinations.
NASA strategists have already begun pointing to the lunar south pole and its possible stockroom of ice as the place of choice for an initial encampment of explorers.

Nailing the lunar ice story

As a first robotic step back to the Moon, NASA is moving out on the Lunar Reconnaissance Orbiter (LRO) and will soon announce the scientific payload this craft will carry. The planning date for LRO launch is October 15, 2008.

"In my view the LRO payload will ‘nail’ the lunar ice story as best one can do from orbit, and pave the way for a surface-based follow on," said Jim Garvin, NASA Chief Scientist in Washington, D.C.

LRO’s powerful payload will enable different measurement approaches that can address the issue of lunar ice in the upper few feet of lunar topside, Garvin told SPACE.com.

"We need a chemical fingerprint," said Alan Stern, a planetary scientist and Director of the Southwest Research Institute's Department of Space Studies here. "If there is water ice in the proportions earlier spacecraft data indicated, and I stress ‘if’…that would be very exciting for exploration and science."

Stern said the ice would have come from meteoritic and cometary sources, or it might have been created by reaction in the lunar soil. LRO and its battery of instruments can basically get at the answer, but it’s clear that the true tale won’t come from any one sensor, he said.

Given independent sensor techniques with different strengths, "LRO can be the definitive mission for both finding and mapping the distribution of lunar ice with enough confidence to send landers/rovers down to specific ice deposits for more detailed study," Stern said.

Delving into water ice by going to the Moon may be like getting a comet sample return, Stern said. "It would be sort of a meta-comet sample return if you find significant quantities."

Perhaps by coring down through layers of lunar ice and finding layers, they would represent different impacts with different parent bodies, Stern suggested. "So that could be very valuable scientifically in terms of understanding comets…which are, of course, relics from the formative days of our solar system. But from an exploration standpoint, it’s about producing water for humans and rocket engines," he added.

Sun shy craters

Europe has already got a jump start on pinpointing what might be lurking in those Sun shy craters. Now looping the Moon is the European Space Agency’s SMART-1 probe.

"SMART-1 is equipped with sensors to peek in the permanent night at the bottom of polar craters," said Bernard Foing, ESA’s Chief Scientist and SMART-1 project scientist.

Foing said SMART-1 ground controllers will use the spacecraft to peer into dark polar targets with sensors for far longer periods of exposure time than for illuminated parts of the Moon. "Even though there is no direct sunlight, the light reflected from the rims of craters could amount to 50 Earthshine…so this could be measurable," he said.

Using SMART-1’s advanced multicolor micro-camera, Foing continued, that device will map and look for albedo variations inside shadowed craters. Albedo is the fraction of light that is reflected by a body or surface.

By employing SMART-1’s Infrared Spectrometer (SIR), Foing said, a search for the "specific spectral fingerprint of water ice" is also scheduled.

"If there are water layers trapped from bombardments from comets and water rich asteroids, a core in lunar ice would give us access to a unique historical record of ice, volatiles and possibly organics that were delivered to the Earth-Moon system," Foing noted.

"If there is not enough water ice there but only enhanced solar wind hydrogen,
future exploration will rely on combining H and O, to make H2O water…like we
do in the chemistry classroom," Foing suggested. "This artificial water might be cleaner to drink than cometary melt!"

Ice picks in the tool kit

There are several science questions that can be addressed by the ability to conduct on-the-spot analyses of ice deposits in the lunar poles, said Ben Bussey, a lunar expert at the John Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

"There is uncertainty as to what is the physical nature of any ice deposit. One scenario is that essentially you have layers with different ice concentrations separated by dry regolith. If this is the case then a core sample would provide information on the impact history of the Earth-Moon system," Bussey pointed out.

Bussey said that geochemical analyses of ice deposits will provide information on the composition of the impacting bodies. Analysis of isotopic ratios of that material should indicate approximately where in the solar system the impactor originated, he said.

While not directly targeted to an on-the-ground study of lunar ice, a Moon landing mission is being assessed by NASA. It could serve as a template for robot landers armed with ice picks in their tool kit.

NASA is reviewing a New Frontiers project dubbed Moonrise – a lunar South Pole-Aitken Basin sample return mission. Michael Duke is Principal Investigator for Moonrise, based at the Colorado School of Mines in Golden.

Moonrise would involve two identical landers on the surface near the Moon's south pole and the return of about five pounds (over two kilograms) of lunar materials from a region of the Moon's surface believed to harbor materials from the mantle of our celestial neighbor, Duke explained.

If Moonrise gets the go-ahead, this mission must be ready for launch no later than June
30, 2010, within a mission cost cap of $700 million.

Harvest Moon

Be it trapped water ice or hydrogen, it’s all good news from the Moon.

That’s the stance of Alan Binder, Director of the Lunar Research Institute in Tucson, Arizona. He was the principal investigator for Lunar Prospector, a NASA Discovery mission launched in January 1998 that operated in lunar orbit for 19 months.

Lunar Prospector found quantities of hydrogen at both the north and south lunar poles. That finding seemed to back data gleaned a few years earlier by the U.S. Pentagon’s Clementine Moon probe. Scientists on the project contend that Clementine revealed the presence of ice at the bottom of a permanently shadowed crater near the Moon's south pole.

"Until we go down on the surface, so to speak, and get absolute confirmation, we can only say that Lunar Prospector found large amounts of hydrogen on the Moon," Binder said.

"It’s totally irrelevant what form the hydrogen is in…whether it’s solar wind implanted hydrogen or whether it is water. We just have to know what equipment to take. That’s because you harvest solar wind hydrogen one way and you harvest the water ice another way. It’s still good news," Binder explained.

"In both cases, it’s the hydrogen that is the valuable thing," Binder concluded, "because there’s plenty of oxygen around. We know that you can crack the rocks and get the metal and oxygen out."

D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/393-9011)

George Diller
Kennedy Space Center, Fla.
(Phone: 321/867-2468)

RELEASE: 04-392

NASA SET TO LAUNCH FIRST COMET IMPACT PROBE

Launch and flight teams are in final preparations for the
planned Jan. 12, 2005, liftoff from Cape Canaveral Air Force
Station, Fla., of NASA's Deep Impact spacecraft. The mission
is designed for a six-month, one-way, 431 million kilometer
(268 million mile) voyage. Deep Impact will deploy a probe
that essentially will be "run over" by the nucleus of comet
Tempel 1 at approximately 37,000 kph (23,000 mph).

"From central Florida to the surface of a comet in six months
is almost instant gratification from a deep space mission
viewpoint," said Rick Grammier, Deep Impact project manager
at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif.
"It is going to be an exciting mission, and we can all
witness its culmination together as Deep Impact provides the
planet with its first man-made celestial fireworks on our
nation's birthday, July 4th," he said.

The fireworks will be courtesy of a 1-by-1-meter (39-by-39
inches) copper-fortified probe. It is designed to obliterate
itself, as it excavates a crater possibly large enough to
swallow the Roman Coliseum. Before, during and after the
demise of this 372-kilogram (820-pound) impactor, a nearby
spacecraft will be watching the 6-kilometer (3.7-mile) wide
comet nucleus, collecting pictures and data of the event.

"We will be capturing the whole thing on the most powerful
camera to fly in deep space," said University of Maryland
astronomy professor Dr. Michael A'Hearn, Deep Impact's
principal investigator. "We know so little about the
structure of cometary nuclei that we need exceptional
equipment to ensure that we capture the event, whatever the
details of the impact turn out to be," he explained.

Imagery and other data from the Deep Impact cameras will be
sent back to Earth through the antennas of the Deep Space
Network. But they will not be the only eyes on the prize.
NASA's Chandra, Hubble and Spitzer space telescopes will be
observing from near-Earth space. Hundreds of miles below,
professional and amateur astronomers on Earth will also be
able to observe the material flying from the comet's newly
formed crater.

Deep Impact will provide a glimpse beneath the surface of a
comet, where material and debris from the solar system's
formation remain relatively unchanged. Mission scientists are
confident the project will answer basic questions about the
formation of the solar system, by offering a better look at
the nature and composition of the celestial travelers we call
comets.

"Understanding conditions that lead to the formation of
planets is a goal of NASA's mission of exploration," said
Andy Dantzler, acting director of the Solar System division
at NASA Headquarters, Washington. "Deep Impact is a bold,
innovative and exciting mission which will attempt something
never done before to try to uncover clues about our own
origins."
With a closing speed of about 37,000 kph (23,000 mph), what
of the washing machine-sized impactor and its mountain-sized
quarry?

"In the world of science, this is the astronomical equivalent
of a 767 airliner running into a mosquito," said Don Yeomans,
a Deep Impact mission scientist at JPL. "It simply will not
appreciably modify the comet's orbital path. Comet Tempel 1
poses no threat to the Earth now or in the foreseeable
future," he added.

Ball Aerospace & Technologies in Boulder, Colo., built NASA's
Deep Impact spacecraft. It was shipped to Florida Oct. 17 to
begin final preparations for launch. Liftoff is scheduled for
Jan. 8 at 1:39:50 p.m. EST, with another opportunity 40
minutes later.

Principal Investigator A'Hearn leads the mission from the
University of Maryland, College Park. JPL manages the Deep
Impact project for the Science Mission Directorate at NASA
Headquarters. Deep Impact is a mission in NASA's Discovery
Program of moderately priced solar system exploration
missions.

For more information about Deep Impact on the Internet,
visit:

http://www.nasa.gov/deepimpact

For more information about NASA and agency programs on the
Internet, visit:

http://www.nasa.gov

-end-

Bill Steigerwald
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-5017)

RELEASE: 04-401

EARTH'S SAFE ZONE BECAME HOT DURING LEGENDARY SOLAR STORMS

A NASA-funded study found a region between radiation belts
surrounding the Earth is not as benign as once thought. The region
was considered a safe zone for satellites in "Middle Earth"
orbits, because of relatively small amounts of radiation.

The observations revealed the Van Allen Radiation Belt Slot, often
considered a safe zone, filled with concentrated radiation during
the ferocious solar storms of October and November 2003. The
radiation surge was the most intense ever observed in this region,
according to researchers.

"Space weather matters. We know that no matter what orbit we
choose, there is the possibility a spacecraft could get blasted by
a significant dose of radiation," said Daniel Baker, Director of
the Laboratory for Atmospheric and Space Physics at the University
of Colorado, Boulder, and lead author of the study. "We need to
take space weather into account when designing spacecraft. We also
need the ability to continuously monitor space weather, so
satellite operators can take protective measures during solar
storms," he said.

High radiation occasionally forms in the safe zone during solar
storms. This radiation is usually not intense and dissipates in a
few days. During the 2003 solar storms, billion-ton eruptions of
electrified gas slammed into the Earth's magnetic field at
millions of miles per hour. This generated powerful electric
fields that forced much of the plasmasphere into interplanetary
space. It was eroded to an unprecedented degree, to the point
below the safe zone. Since the plasmasphere was below the safe
zone, an intense radiation belt powered by the solar storms formed
in the region.

If the Van Allen radiation belts were visible from space, they
would resemble a pair of donuts around the Earth, one inside the
other with the planet in the hole of the innermost one. The safe
zone would appear as a gap between the inner and outer donut,
beginning about 7,000 km (4,350 miles) and ending approximately
13,000 km (8,110 miles) above the Earth's surface. The belts are
comprised of high-speed electrically charged electrons and atomic
nuclei trapped in the Earth's magnetic field.

The Solar, Anomalous and Magnetospheric Particle Explorer (SAMPEX)
satellite flies through these belts, taking measurements of the
particle types, their energy and abundance. SAMPEX observed the
formation of the new belt in the safe zone on October 31, 2003.
The radiation remained intense for about two weeks, and then
gradually dissipated.

NASA's Imager for Aurora to Magnetopause Global Exploration
(IMAGE) satellite observed the loss of the plasmasphere during the
solar storms. Since solar ultraviolet radiation energizes helium
ions in the plasmasphere, causing them to glow in ultraviolet
light, the Extreme Ultraviolet Imager instrument on IMAGE can
record the extent of the plasmasphere by observing this glow.

IMAGE discovered the plasmasphere was at its lowest point on
October 31, 2003. The plasmasphere slowly expanded past the safe
zone, replenished by particles from Earth's upper atmosphere.
After its expansion beyond the safe zone, SAMPEX observed the
dissipation of the new radiation belt.

"We were surprised to see the radiation belt persist so long after
the plasmasphere expanded past the safe zone," said Jerry
Goldstein of the Southwest Research Institute (SwRI), San Antonio,
a co-author of the paper. "Radiation in the safe zone remained
strong for a few weeks, a lot longer than usual," he said.

The research used theory, modeling, and observations from work
sponsored by the National Science Foundation and the National
Oceanic and Atmospheric Administration. The research team included
Drs. Shri Kanekal, Xinlin Li, and Steven Monk also of the
University of Colorado and Dr. James Burch of SwRI.

The research data was presented today during the American
Geophysical Union Fall meeting in San Francisco, and it appears
tomorrow in the journal Nature. For more information about the
research and images on the Web, visit:

http://www.nasa.gov/vision/universe/solarsystem/safe_zone.html

For information about NASA and agency research programs on the
Web, visit:

http://www.nasa.gov
-end-

* * *

Astronomers spotted an asteroid this week after it had flown past Earth on a course that took it so close to the planet it was below the orbits of some satellites.

The space rock was relatively small, however, and would not have posed any danger had it plunged into the atmosphere.

The object, named 2004 YD5, was about 16 feet (5 meters) wide, though that's a rough estimate based on its distance and assumed reflectivity. Had it entered the atmosphere, it would have exploded high up, experts figure.

Satellite territory

The asteroid passed just under the orbits of geostationary satellites, which at 22,300 miles (36,000 kilometers) altitude are the highest manmade objects circling Earth. Most other satellites, along with the International Space Station, circle the planet at just a few hundred miles up.

2004 YD5 is the second closest pass of an asteroid ever observed by telescope, according to the Asteroid/Comet Connection, a web site that monitors space rock discoveries. The closest involved a rock that flew by last March and was not announced until August.

2004 YD5 was discovered Tuesday, Dec. 21 by Stan Pope, who volunteers his time to examine images provided by the FMO (Fast Moving Object) project, an online program run by the University of Arizona's Spacewatch Project. After the initial detection, other observers noted the object's position during the day and its path was then calculated back. Closest approach occurred on Dec. 19.

The rock approached Earth from near the Sun and so would have been nearly impossible to detect prior to close passage. It soared over Antarctica -- underneath the planet, Washington State University researcher Pasquale Tricarico told the Asteroid/Comet Connection.

Astronomers are aware of this significant blind spot for asteroids that approach Earth while in the glare of the Sun. Only a space telescope could detect such objects before they arrive.

Similar events

Asteroids orbit the Sun, mostly in a belt between Mars and Jupiter. Some are redirected closer to the Sun, often by gravitational nudges provided by the planets. Earth has been hit by devastatingly large asteroids many times in the distant past. Astronomers say sooner or later the planet will be struck again, but the odds of a large impact occurring in any given century are extremely small.

This has been an interesting year for asteroid encounters.

On March 18, a giant boulder about 100 feet (30 meters) wide passed just above the orbits of geostationary satellites. Its path was bent about 15 degrees by Earth's gravity. The asteroid, 2004 FH, was discovered a mere three days prior.

On Sept. 29, the largest asteroid ever known to pass near Earth, named Toutatis, roamed by at about four times the distance to the Moon. Astronomers had known for years the flyby would occur, since Toutatis is 2.9 miles (4.6 kilometers) long and had been in Earth's vicinity before.

But many near misses by small asteroids likely go unnoticed, astronomers say, because the entire sky is not continuously monitored. Such small asteroids have been detected only in recent years as more sophisticated telescopes have been hooked up with digital cameras.

And some asteroids come even closer, entering the atmosphere. Most never reach the ground because they break apart under the stress of entry. One study of data collected by U.S. military satellites logged 300 in-air asteroid explosions.

2004 YD5 was announced Tuesday evening by the Minor Planet Center in Cambridge, Mass, where comet and asteroid observations from around the globe are digested.

I tried the basic explanations, but I can't say it clarified anything. The advanced explanations, now that is somewhere else.........

Supposedly I am good at math, but physics, another story

Dolores Beasley
Headquarters, Washington January 5, 2005
(Phone: 202/358-1753)

Steve Roy
Marshall Space Flight Center, Huntsville, Ala.
(Phone: 256/544-6535)

Megan Watzke
Chandra X-ray Observatory Center, Cambridge, Mass.
(Phone: 617/496-7998)

RELEASE: 05-004

MOST POWERFUL ERUPTION IN THE UNIVERSE DISCOVERED

Astronomers have found the most powerful eruption in the
universe using NASA's Chandra X-ray Observatory. A super
massive black hole generated this eruption by growing at a
remarkable rate. This discovery shows the enormous appetite
of large black holes, and the profound impact they have on
their surroundings.

The huge eruption was seen in a Chandra image of the hot, X- ray emitting gas of a galaxy cluster called MS 0735.6+7421.
Two vast cavities extend away from the super massive black
hole in the cluster's central galaxy. The eruption, which has
lasted for more than 100 million years, has generated energy
equivalent to hundreds of millions of gamma-ray bursts.

This event was caused by gravitational energy release, as
enormous amounts of matter fell toward a black hole. Most of
the matter was swallowed, but some of it was violently
ejected before being captured by the black hole. "I was
stunned to find that a mass of about 300 million suns was
swallowed," said Brian McNamara of Ohio University in Athens.
"This is as large as another super massive black hole." He is
lead author of the study about the discovery, which is in the
January 6, 2005, issue of Nature.

Astronomers are not sure where such large amounts of matter
came from. One theory is gas from the host galaxy
catastrophically cooled and was swallowed by the black hole.
The energy released shows the black hole in MS 0735 has grown
dramatically during this eruption. Previous studies suggest
other large black holes have grown very little in the recent
past, and that only smaller black holes are still growing
quickly.

-more-
-2-
"This new result is as surprising as it is exciting," said
co-author Paul Nulsen of the Harvard-Smithsonian Center for
Astrophysics, Cambridge, Mass. "This black hole is feasting,
when it should be fasting."

Radio emission within the cavities shows jets from the black
hole erupted to create the cavities. Gas is being pushed away
from the black hole at supersonic speeds over a distance of
about a million light-years. The mass of the displaced gas
equals about a trillion suns, more than the mass of all the
stars in the Milky Way.

The rapid growth of super massive black holes is usually
detected by observing very bright radiation from the centers
of galaxies in the optical and X-ray wavebands, or luminous
radio jets. In MS 0735 no bright central radiation is found,
and the radio jets are faint. The true nature of MS 0735 is
only revealed through X-ray observations of the hot cluster
gas.

"Until now we had no idea this black hole was gorging
itself," said co-author Michael Wise of the Massachusetts
Institute of Technology, Cambridge, Mass. "The discovery of
this eruption shows X-ray telescopes are necessary to
understand some of the most violent events in the universe."

The astronomers estimated how much energy was needed to
create the cavities by calculating the density, temperature
and pressure of the hot gas. By making a standard assumption
that 10 percent of the gravitational energy goes into
launching the jets, they estimated how much material the
black hole swallowed.

Besides generating the cavities, some of the energy from this
eruption should keep the hot gas around the black hole from
cooling, and some of it may also generate large-scale
magnetic fields in the galaxy cluster. Chandra observers have
discovered other cavities in galaxy clusters, but this one is
easily the largest and the most powerful.

NASA's Marshall Space Flight Center, Huntsville, Ala.,
manages the Chandra program for NASA's Space Mission
Directorate, Washington. Northrop Grumman of Redondo Beach,
Calif., was the prime development contractor for the
observatory. The Smithsonian Astrophysical Observatory
controls science and flight operations from the Chandra X-ray
Center in Cambridge, Mass.

Additional information and images from Chandra are available
on the Web at:

http://chandra.harvard.edu
& http://chandra.nasa.gov

-end-

Dolores Beasley
Headquarters, Washington January 5, 2005
(Phone: 202/358-1753)

Nancy Neal-Jones
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-0039)

RELEASE: 05-005

NASA SWIFT MISSION TURNS ON AND SEES A BLAST OF BURSTS

The NASA-led Swift mission opened its doors to a flurry of gamma
ray burst action.

Scientists were still calibrating the main instrument, the Burst Alert
Telescope (BAT), when the first burst appeared on December 17. Three
bursts on December 19, and one on December 20, followed.

Swift's primary goal is to unravel the mystery of gamma ray bursts. The
bursts are random and fleeting explosions, second only to the Big Bang
in total energy output. Gamma rays are a type of light millions of
times more energetic than light human eyes can detect. Gamma ray bursts
last only from a few milliseconds to about one minute. Each burst
likely signals the birth of a black hole.

"The optimists among us were hoping to detect two bursts a week, not
three in one day just after turning the telescope on," said Dr. Scott
Barthelmy, the BAT lead scientist at NASA's Goddard Space Flight
Center, Greenbelt, Md. "Maybe we got lucky, or maybe we've
underestimated the true rate of these bursts. Only time will tell," he
added.

Once the BAT, that covers about one-seventh of the sky at any time,
detects a gamma ray burst, it quickly relays a location to the ground.
Within about one minute, the satellite automatically turns toward the
burst. The move brings the burst within view of Swift's two other
telescopes: the X-ray Telescope (XRT) and the Ultraviolet/Optical
Telescope (UVOT).

Once all three instruments are turned on and calibrated, Swift will get
down to the business of analyzing gamma ray bursts. "The universe kept
up its side of the bargain, and we kept up ours," said Dr. Neil
Gehrels, Swift's Principal Investigator at Goddard. "This is going to
be an exciting mission," he said.

The Swift team tested the BAT by observing Cygnus X-1, a well-known
bright source that produces gamma rays in our galaxy. It is thought to
be a black hole in orbit around a star. The team called this BAT's
"first light."

The BAT is the most sensitive gamma ray detector ever flown. The BAT
employs a novel technology to image and locate gamma ray bursts. Unlike
visible light, gamma rays pass right through telescope mirrors and
cannot be reflected onto a detector. The BAT uses a technique called
"coded aperture mask" to create a gamma ray shadow on its detectors.
The mask contains 52,000 randomly placed lead tiles that block some
gamma rays from reaching the detectors. With each burst, some detectors
light up while others remain dark, shaded by the lead tiles. The angle
of the shadow points back to the gamma ray burst.

"The BAT coded aperture mask is about the size of a pool table, the
largest and most intricate ever fabricated," said Ed Fenimore of Los
Alamos National Laboratory, N.M. Los Alamos created the BAT software.
"BAT can accurately pinpoint a burst within seconds and detect bursts
five times fainter than previous instruments," he added.

Swift, a medium-class explorer mission managed by Goddard, was launched
from Cape Canaveral on November 20, 2004. The mission is in
participation with the Italian Space Agency and the Particle Physics
and Astronomy Research Council in the United Kingdom.

Swift was built at Goddard in collaboration with General Dynamics,
Ariz.; Penn State University, College Station, Pa.; Sonoma State
University, Rohnert Park, Calif.; Los Alamos; Mullard Space Science
Laboratory, Surrey, England; the University of Leicester, England; the
Brera Observatory, Milan, Italy; and ASI Science Data Center, Rome.

Images of the BAT's "first light" and Swift's first bursts are on the
Internet at:

http://www.nasa.gov/vision/universe/watchtheskies/swift_first_light.htm
l

For more information about NASA and agency programs on the Internet,
visit:

http://www.nasa.gov

-end-

* * *

The Sun Goes Wild

The Sun ended 2004 with a bang, firing off one of the most unusual eruptions scientists have ever seen.

The complex eruption is called a coronal mass ejection (CME). It originated from a region of the solar surface where pent-up magnetic energy was unleashed. Superheated gas, called plasma, was flung into space. All that is normal.

But in this case, several white strands of plasma elongated and lingered "longer than anyone can remember seeing," said Paal Brekke of the Norwegian Space Center. The strands were visible to scientists over a nine-hour stretch.

"The pieces appear almost like shreds of torn clothing after something ripped through it," Brekke said. "They clearly illustrate how a CME drags pieces of the Suns magnetic field out in space."

In this picture, the overwhelming light of the Sun's main disk is blocked out by an instrument aboard the Solar and Heliospheric Observatory (SOHO) spacecraft, allowing it to capture the action in the solar atmosphere and beyond.

SAN DIEGO -- Astronomers are highly confident that they've taken the first photograph of a planet outside our solar system.

Make that two photographs.

A new image from the Hubble Space Telescope confirms with a high degree of confidence a picture made previously by astronomers at the European Southern Observatory (ESO) and reported by SPACE.com in September.

The planet -- still just a candidate, actually -- is an odd duck in many respects. It does not orbit a normal star, and it is much more massive than the largest planets in our solar system.

Still, if confirmed, it represents a landmark in astronomy along the road to the ultimate goal of finding and photographing Earth-like planets around other stars.

The Hubble image was released here today at a meeting of the American Astronomical Society.

The planet candidate appears to orbit a failed star known as a brown dwarf. The initial observations at ESO's Very Large Telescope could not determine whether the apparent planet was actually at the same distance as the brown dwarf or if it was a background object. The Hubble observations show that the two indeed appear to be travelling together through the sky, suggesting they are gravitationally bound, as originally suspected.

University of Arizona astronomer Glenn Schneider, who led the new study, said he's 99.1 percent sure the object is in orbit around the brown dwarf. He expects to be 99.9 percent sure in April when more Hubble observations are made as the planet presumably moves a bit farther along in its orbit.

"Stay tuned for the final confirmation, but it's looking pretty good," Schneider said.

The planet candidate is about 1.5 times the diameter of Jupiter and about five times as massive. It orbits the brown dwarf star at about 30 percent farther than Pluto is from our Sun. The brown dwarf does not have enough mass to trigger thermonuclear fusion and shine like a normal star, but it is also outside the realm of planethood, being some 25 times more massive than Jupiter and glowing with infrared light.

The setup is about 225 light-years away.

"This is the first image of a planet outside our solar system," said UCLA astronomer Eric Becklin, quickly correcting himself to say it was an image most likely to be of an extrasolar planet. "So we really need to be sure."

Becklin and others eagerly await the April observations.

If confirmed, the finding would have "enormous impact" on the ability of astronomers to get funding for future telescopes that would look for Earth-like planets, said Steve Maran, press officer of the American Astronomical Society.

And what to make of a planet orbiting a failed star? Astronomers are already debating what constitutes a planet and whether the definition should include how they formed versus what they orbit.

Becklin, who was not involved in the imaging, said there is evidence for planets orbiting planets and planets floating alone in space with no star. If the latest image is proved to be what it seems, that would suggest "planets are around a lot of things," he said.

Inquiring minds want to know

BTW, if you like BIG, check out the Size Blue Ribbon holder of stars :

Thanks for the picture Vgkg. I was hoping for something more dramatic, but I understand the limitations.

ET Visitors: Scientists See High Likelihood
By Leonard David
Senior Space Writer
posted: 14 January 2005
06:47 am ET

Decades ago, it was physicist Enrico Fermi who pondered the issue of extraterrestrial civilizations with fellow theorists over lunch, generating the famous quip: "Where are they?" That question later became central to debates about the cosmological census count of other star folk and possible extraterrestrial (ET) visitors from afar.

Fermi’s brooding on the topic was later labeled "Fermi’s paradox". It is a well-traveled tale from the 1950’s when the scientist broached the subject in discussions with colleagues in Los Alamos, New Mexico. Thoughts regarding the probability of earthlike planets, the rise of highly advanced civilizations "out there", and interstellar travel -- these remain fodder for trying to respond to Fermi’s paradox even today.

Now a team of American scientists note that recent astrophysical discoveries suggest that we should find ourselves in the midst of one or more extraterrestrial civilizations. Moreover, they argue it is a mistake to reject all UFO reports since some evidence for the theoretically-predicted extraterrestrial visitors might just be found there.

The researchers make their proposal in the January/February 2005 issue of the Journal of the British Interplanetary Society (JBIS).

Curious situation

Pick up any good science magazine and you’re sure to see the latest in head-scratching ideas about superstring theory, wormholes, or the stretching of spacetime itself. Meanwhile, extrasolar planetary detection is on the verge of becoming mundane.

"We are in the curious situation today that our best modern physics and astrophysics theories predict that we should be experiencing extraterrestrial visitation, yet any possible evidence of such lurking in the UFO phenomenon is scoffed at within our scientific community," contends astrophysicist Bernard Haisch.

Haisch along with physicists James Deardorff, Bruce Maccabee and Harold Puthoff make their case in the JBIS article: "Inflation-Theory Implications for Extraterrestrial Visitation".

The scientists point to two key discoveries made by Australian astronomers and reported last year that there is a "galactic habitable zone" in our Milky Way Galaxy. And more importantly that Earth’s own star, the Sun, is relatively young in comparison to the average star in this zone -- by as much as a billion years.

Therefore, the researchers explain in their JBIS article that an average alien civilization would be far more advanced and have long since discovered Earth. Additionally, other research work on the supposition underlying the Big Bang -- known as the theory of inflation -- shores up the prospect, they advise, that our world is immersed in a much larger extraterrestrial civilization.

Point-to-point distances

Given billion-year advanced physics, might not buzzing around the galaxy be possible?

Even today superstring theory hypothesizes other dimensions... which could be habitable Universes adjacent to our own, the researchers speculate. It might even be possible to get around the speed of light limit by moving in and out of these dimensions.

"What we have done is somewhat of a breakthrough," Haisch told SPACE.com. "We have pulled together various recent discoveries and theoretical issues that collectively point to the strong probability that we should be in the midst of one or more huge extraterrestrial civilizations," he said.

Haisch said that superstring dimensions and wormhole and spacetime stretching possibilities address the "can't get here from there" objection often argued in view of the interstellar, point-to-point distances involved. Also, diffusion models predict that even a single civilization could spread across the Galaxy in a tiny fraction of the age of the Galaxy - even at sub-light speeds, he said.

ET signature in the data

Can the scientific community bring itself to consider any evidence coming from mysterious sightings of strange things by the public?

In large measure, the scientific community seemingly has eyed ET visitation as far from being serious stuff to cogitate over. Why so?

"The dismissal has several causes, all reinforcing each other," Haisch responded. "Most of
the observations are probably misinterpretations, delusions and hoaxes. I have seen people get confused by Venus or even Sirius when it is flashing colors low in the sky under the right conditions. Having been turned off by this, most scientists never bother to look any further, and so are simply blissfully ignorant that there may be more to it," he said.

Deardorff, the lead author of the JBIS article, points out in a press statement: "It would take some humility for the scientific community to suspend its judgment and take at least some of the high quality reports seriously enough to investigate…but I hope we can bring ourselves to do that."

According to Haisch, there is a motivation not just for scientific tolerance of the UFO issue, but a strong scientific prediction that there ought to be some genuine ET signature in the data.

"This potentially changes the relationship of the UFO phenomenon to science in a significant way. It takes away the ‘not invented here’ prejudice, pointing out that a ‘yes’ to ET visitation is exactly what side our current physics and astrophysics theories would come down on as the most likely situation," Haisch concluded.

The flare was classified as X-3. All X-class flares are considered major, with the number indicated a degree of severity. Its radiation traveled at light-speed, arriving at Earth within minutes and, along the way, swamping a detector on the Solar and Heliospheric Observatory (SOHO) spacecraft, which monitors the Sun and its storms.

Along with the flare came a billowing cloud of charge particles known as a coronal mass ejection (CME). Travelling at millions of miles per hour, CMEs take anywhere from about 17 hours to two or three days to reach Earth.

Scientists expect this CME [animation] to arrive overnight Tuesday or sometime Wednesday.

The CME is likely to trigger the Northern Lights, also known as aurora. These waves and wisps of red, yellow and green are created when charged particles excite molecules in the upper atmosphere, causing them to glow.

"Extreme geomagnetic storms are possible when it arrives on Jan. 18 or 19," reads a statement on Spaceweather.com, a NASA-run web site that monitors solar storms and their effects.

The storm lifted off of a region of sunspots [image] catalogued as 720. Sunspots are cool regions of the Sun's surface that harbor pent-up magnetic energy. When unleashed, light, X-rays and charged particles are flung into space.

The sunspot group is rotating toward the limb of the Sun and could produce more major flares before it heads around to the back side in a few days.

During severe space storms, the aurora can sometimes be seen from middle latitudes, such as the lower United States and Europe. Scientists cannot predict how far south the lights will dip in any given storm, however. The effect depends largely on how Earth's magnetic field is aligned as a storm arrives.

--------------------------------------------------------------------------------

Northern Lights in November, 2004

SOHO's Greatest Hits

--------------------------------------------------------------------------------
Depending on conditions, the storm could provide a fascinating display for several hours or it could be a dud.

The show, if there is one, could well play out in the predawn hours Wednesday for North American skywatchers.

A previous CME that buffeted the planet late Monday into early Tuesday morning generated strong aurora for residents in Alaska and other parts of the far North. Strong lights were spotted also in Minnesota, and faint colorings were seen as far south as Maryland. A Chicago resident reported "a great show" even under the glare of bright city lights.

Earth's geomagnetic field, where the aurora develop, "is expected to continue at major to severe storm levels," according to a statement from NOAA's Space Environment Center, the otherworldly counterpart to the National Weather Service.

In general, the Sun is near a minimum of activity in a roughly 11-year cycle. But sunspots, flares and eruptions can occur anytime during the cycle, scientists have learned.

Nancy Neal-Jones
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-0039)

RELEASE: 05-019

SWIFT MISSION IMAGES THE BIRTH OF A BLACK HOLE

The NASA-led Swift mission has detected and imaged its first gamma-ray
burst, likely the birth cry of a brand new black hole.

The bright and long burst occurred on January 17. It was in the midst of
exploding, as Swift autonomously turned to focus in less than 200 seconds. The
satellite was fast enough to capture an image of the event with its X-Ray
Telescope (XRT), while gamma rays were still being detected with the Burst Alert
Telescope (BAT).

"This is the first time an X-ray telescope has imaged a gamma-ray burst, while it
was bursting," said Dr. Neil Gehrels, Swift's Principal Investigator at NASA's
Goddard Space Flight Center, Greenbelt, Md. "Most bursts are gone in about 10
seconds, and few last upwards of a minute. Previous X-ray images have captured
the burst afterglow, not the burst itself."

"This is the one that didn't get away," said Prof. John Nousek, Swift's Mission
Operations Director at Penn State University, State College, Pa. "And this is
what Swift was built to do: to detect these fleeting gamma-ray bursts and focus
its telescopes on them autonomously within about a minute. The most exciting
thing is this mission is just revving up."

Swift has three main instruments. The BAT detects bursts and initiates the
autonomous slewing to bring the XRT and the Ultraviolet/Optical Telescope (UVOT)
within focus of the burst. In December the BAT started detecting bursts,
including a remarkable triple detection on December 19. Today's announcement
marks the first BAT detection autonomously followed by XRT detection,
demonstrating the satellite is swiftly slewing as planned. The UVOT is still
being tested, and it was not collecting data when the burst was detected.

Scientists will need several weeks to fully understand this burst, GRB050117, so
named for the date of detection. Telescopes in orbit and on Earth will turn to
the precise burst location provided by Swift to observe the burst afterglow and
the region surrounding the burst.

"We are frantically analyzing the XRT data to understand the X-ray emission seen
during the initial explosion and the very early afterglow," said Dr. David
Burrows, the XRT lead at Penn State. "This is a whole new ballgame. No one has
ever imaged X-rays during the transition of a gamma-ray burst from the brilliant
flash to the fading embers."

When the UVOT is fully operational, both the XRT and UVOT will provide an in- depth observation of the gamma-ray burst and its afterglow. The burst is gone in
a flash, but scientists can study the afterglow to learn about what caused the
burst, much like a detective hunts for clues at a crime scene.

The origin of gamma-ray bursts remains a mystery. At least some appear to
originate in massive star explosions. Others might be the result of merging black
holes or neutron stars. Any of these scenarios likely will result in the
formation of a new black hole.

Several of these bursts occur daily somewhere in the visible universe. No prompt
X-ray emission (coincident with the gamma-ray burst) has been previously imaged,
because it usually takes hours to turn an X-ray telescope towards a burst.
Scientists expect Swift to be fully operational by February 1.

Swift, still in its checkout phase, is an international collaboration launched on
November 20, 2004. It is a NASA mission in partnership with the Italian Space
Agency and the Particle Physics and Astronomy Research Council, United Kingdom.

The spacecraft was built in collaboration with national laboratories,
universities and international partners, including Penn State University; Los
Alamos National Laboratory, New Mexico; Sonoma State University, Rohnert Park,
Calif.; Mullard Space Science Laboratory in Dorking, Surrey, England; the
University of Leicester, England; Brera Observatory in Milan; and ASI Science
Data Center in Frascati, Italy.

For more information about Swift on the Web, visit:

http://swift.gsfc.nasa.gov

-end-

* * *

NASA is returning to the Moon--not just robots, but people. In the decades ahead we can expect to see habitats, greenhouses and power stations up there. Astronauts will be out among the moondust and craters, exploring, prospecting, building.

Last week, though, there were no humans walking around on the Moon.

Good thing.

On Jan. 20, 2005, a giant sunspot named "NOAA 720" exploded. The blast sparked an X-class solar flare, the most powerful kind, and hurled a billion-ton cloud of electrified gas (a "coronal mass ejection") into space. Solar protons accelerated to nearly light speed by the explosion reached the Earth-Moon system minutes after the flare--the beginning of a days-long "proton storm."

Here on Earth, no one suffered. Our planet's thick atmosphere and magnetic field protects us from protons and other forms of solar radiation. In fact, the storm was good. When the plodding coronal mass ejection arrived 36 hours later and hit Earth's magnetic field, sky watchers in Europe saw the brightest and prettiest auroras in years.

The Moon is a different story.

"The Moon is totally exposed to solar flares," explains solar physicist David Hathaway of the Marshall Space Flight Center. "It has no atmosphere or magnetic field to deflect radiation." Protons rushing at the Moon simply hit the ground--or whoever might be walking around outside.

The Jan. 20 proton storm was by some measures the biggest since 1989. It was particularly rich in high-speed protons packing more than 100 million electron volts (100 MeV) of energy. Such protons can burrow through 11 centimeters of water. A thin-skinned spacesuit would have offered little resistance.

"An astronaut caught outside when the storm hit would've gotten sick," says Francis Cucinotta, NASA's radiation health officer at the Johnson Space Center. At first, he'd feel fine, but a few days later symptoms of radiation sickness would appear: vomiting, fatigue, low blood counts. These symptoms might persist for days.

Astronauts on the International Space Station (ISS), by the way, were safe. The ISS is heavily shielded, plus the station orbits Earth inside our planet's protective magnetic field. "The crew probably absorbed no more than 1 rem," says Cucinotta.

One rem, short for Roentgen Equivalent Man, is the radiation dose that causes the same injury to human tissue as 1 roentgen of x-rays. A typical dental x-ray, for example, delivers about 0.1 rem. So, for the crew of the ISS, the Jan. 20 proton storm was like 10 trips to the dentist--scary, but no harm done.

On the Moon, Cucinotta estimates, an astronaut protected by no more than a space suit would have absorbed about 50 rem of ionizing radiation. That's enough to cause radiation sickness. "But it would not have been fatal," he adds.

To die, you'd need to absorb, suddenly, 300 rem or more.

The key word is suddenly. You can get 300 rem spread out over a number of days or weeks with little effect. Spreading the dose gives the body time to repair and replace its own damaged cells. But if that 300 rem comes all at once ... "we estimate that 50% of people exposed would die within 60 days without medical care," says Cucinotta.

Such doses from a solar flare are possible. To wit: the legendary solar storm of August 1972.

It's legendary (at NASA) because it happened during the Apollo program when astronauts were going back and forth to the Moon regularly. At the time, the crew of Apollo 16 had just returned to Earth in April while the crew of Apollo 17 was preparing for a moon-landing in December. Luckily, everyone was safely on Earth when the sun went haywire.

"A large sunspot appeared on Aug. 2, 1972, and for the next 10 days it erupted again and again," recalls Hathaway. The spate of explosions caused, "a proton storm much worse than the one we've just experienced," adds Cucinotta. Researchers have been studying it ever since.

Cucinotta estimates that a moonwalker caught in the August 1972 storm might have absorbed 400 rem. Deadly? "Not necessarily," he says. A quick trip back to Earth for medical care could have saved the hypothetical astronaut's life.

Surely, though, no astronaut is going to walk around on the Moon when there's a giant sunspot threatening to explode. "They're going to stay inside their spaceship (or habitat)," says Cucinotta. An Apollo command module with its aluminum hull would have attenuated the 1972 storm from 400 rem to less than 35 rem at the astronaut's blood-forming organs. That's the difference between needing a bone marrow transplant … or just a headache pill.

Modern spaceships are even safer. "We measure the shielding of our ships in units of areal density--or grams per centimeter-squared," says Cucinotta. Big numbers, which represent thick hulls, are better:

The hull of an Apollo command module rated 7 to 8 grams per square centimeter (g/cm2).

A modern space shuttle has 10 to 11 g/cm2.

The hull of the ISS, in its most heavily shielded areas, has 15 g/cm2.

Future moonbases will have storm shelters made of polyethelene and aluminum possibly exceeding 20 g/cm2.

A typical space suit, meanwhile, has only 0.25 g/cm2, offering little protection. "That's why you want to be indoors when the proton storm hits," says Cucinotta.

But the Moon beckons and when explorers get there they're not going to want to stay indoors. A simple precaution: Like explorers on Earth, they can check the weather forecast--the space weather forecast. Are there any big 'spots on the sun? What's the chance of a proton storm? Is a coronal mass ejection coming?

All clear? It's time to step out.

Orbital Overload: Space Debris Crowds the Not-So-Friendly Skies

By Leonard David
Senior Space Writer
posted: 02 February 2005
06:47 am ET

As dump-sites go, there’s nothing quite like Earth orbit: Totally gone or near-dead spacecraft, spent motor casings and rocket stages, all the way down to pieces of solid propellant, insulation, and paint flakes. Toss in for good measure thousands of frozen bits of still-radioactive nuclear reactor coolant dribbling from a number of aged Russian radar satellites.

Here’s the heavenly clutter count as of December 29, 2004.

There were 9,233 objects large enough to be tracked and catalogued by the USSTRATCOM Space Surveillance Network. Of this total there were 2,927 payloads, along with 6,306 object classed as rocket bodies and debris.

That’s the stats as listed in the January issue of The Orbital Debris Quarterly News, issued by the NASA Johnson Space Center Orbital Debris Program Office in Houston, Texas.

Hardware survivors

A major contributor to orbital debris is an object suddenly breaking up. This can be caused when propellant and oxidizer inadvertently mix; leftover fuel becomes overpressurized due to heating; or when onboard batteries blow their tops. Some spacecraft have been purposely detonated. Explosions can also be indirectly triggered by collisions with fast-moving debris.

An example of fragmentation took place last October. A Russian Proton Block DM auxiliary motor busted up, adding more than 60 pieces of junk to the overall orbital debris scene.

At times some of this high-tech scrap survives its fiery plunge through Earth’s atmosphere. A growing list of these hardware survivors is maintained by The Center for Orbital and Reentry Debris Studies at The Aerospace Corporation in El Segundo, California.

Last year, for instance, a titanium rocket-motor casing weighing roughly 155 pounds (70 kilograms) was found near San Roque in Argentina. It was identified as debris from a third stage of an American Delta 2 booster that had been orbiting since October 1993.

Similarly, in July a metal pressure sphere and metal fragment fell into Brazil, the likely debris from a second stage of a Delta 2 booster that hurled the Mars Exploration Rover, Opportunity, toward the red planet a year earlier.

Solar max and minimum

So what’s the overall report card on orbiting trash look like over the years?

Fragmentation debris appears to have decreased noticeably in recent years, but unfortunately the true picture is slightly different, said Nicholas Johnson, Program Manager and Chief Scientist of the NASA Orbital Debris Program Office at the Johnson Space Center in Houston, Texas.

"A significant number of fragmentation debris objects have been created during the period and are being tracked by the Space Surveillance Network, but they have not yet been officially cataloged," Johnson told SPACE.com. "This is a bureaucratic issue rather than an environmental one. Meanwhile, spacecraft and rocket bodies continue to accumulate, although for the latter the rate of increase is now small."

There’s another "message" that can be seen in charting out the space junk saga, found in the relative numbers of spacecraft, rocket bodies, and other debris.

Johnson said that that we are nearing solar minimum when reentries -- particularly for small debris -- normally taper off. There was a clear decrease in the population around 1990 during a period of high solar activity. "Unfortunately, the last solar max did not produce a similar result," he said.

Fall of Hubble

So far this month there have been a couple of U.S. Delta rocket stages that have reentered, as well as a Russian Proton motor.

All this is small stuff compared to something big coming in on its own -- like the Hubble Space Telescope. There’s good reason why an eventual "controlled" reentry is being planned for that orbiting eye on the universe.

Orbital debris analysts have figured out the risk to humans down below if Hubble should plow through the Earth’s atmosphere in an uncontrolled manner.

At least two tons (2,055 kilograms) of the estimated 26,000 pounds (11,792 kilograms) of the observatory would survive the plummet from space. Such a fall would produce a debris track that stretches over 755 miles (1,220 kilometers) in length. The analysis suggests that the risk posed to the human population in the year 2020 is 1:250 -- a risk that exceeds NASA’s own safety standard.

The center of the Milky Way is a packed place for stars.

In this image, the deepest-ever infrared view into part of the galactic center, thousands of stars are crammed into an area just six light-years across (Earth's closest neighboring star - Proxima Centauri - is 4.2 light years away). But the locations of bright stars don't match locations of X-ray sources previously discovered by NASA's Chandra X-ray Observatory, indicating that the galactic center may contain many faint Sun-like stars with X-ray-emitting white dwarf companions.

This deepest-ever infrared view of a region near the galactic center shows thousands of stars crowded into an area only 6 light-years across. One light-year is the distance light travels in one year, about 5.88 trillion miles (9.64 trillion kilometers). Astronomers used infrared observations from the 6.5-meter Magellan Telescope in Chile to peer past obscuring dust into the galactic center. The research was announced during the 205th meeting of the American Astronomical Society earlier this year.

If the X-ray sources near the galactic center are accreting white dwarfs, the large numbers of compact low-mass binaries required could suggest that they formed in the very dense star cluster around the galactic center or that they have been "deposited" there by the destruction of globular clusters. Deeper infrared observations and spectra of the sources are needed to make actual identifications and constrain the masses of the accreting compact objects.

-- SPACE.com Staff

For a 2-D comparison here's what our stellar neighborhood looks like :

Mike Mewhinney Feb. 14, 2005
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650/604-3937 or 650/604-9000
E-mail: Michael.Mewhinney@nasa.gov

NEWS RELEASE: 05-07AR

NASA AWARDS CONTRACT FOR KEPLER MISSION PHOTOMETER

NASA Ames Research Center, located in California's Silicon Valley,
has awarded a new contract to Ball Aerospace and Technologies Corp.
(BATC) of Boulder, Colo., to design, fabricate, assemble and test a
photometer for the Kepler mission.

The not-to-exceed value of this letter contract is $13.4 million; the
estimated value of the total contract is $75.1 million, which is part
of a five-phased acquisition. A cost-plus-incentive-fee contract is
anticipated, with a three-year period of performance that does not
include any contract options.

Under the terms of the contract, Ball Aerospace is responsible for
designing, fabricating, integrating, testing and commissioning the
scientific instrument called the photometer. Under a separate
contract, the corporation also is responsible for the three-axis
stabilized spacecraft designed to operate in deep space.

The Kepler mission is the first space mission specifically designed
to detect Earth-size planets orbiting solar-like stars in their
habitable zone. The habitable zone is that distance from a star where
liquid water could exist on the surface of the planet.

Scheduled to launch in October 2007 on a Boeing Delta II expendable
launch vehicle, Kepler is the 10th mission in NASA's Discovery
program series. Project scientists will survey our extended solar
neighborhood to detect and characterize hundreds of terrestrial and
larger planets to provide a greater understanding of planetary
systems.

The photometer will be used to measure the very small changes in a
star's brightness caused by the repeated, periodic 'transit' of a
planet in front of its star, as viewed from our solar system, similar
to the transit of Venus in front of the sun in June 2004. The focal
plane of the photometer will be made up of light-sensing charge
coupled devices (CCDs) similar to those in a digital camera, but much
larger, with a total of 100 megapixels.

The photometer will survey a single, large patch of sky for the
entire four-year mission, an area equivalent in size to two open
hands held together at arms' length. The location in the sky is in
the Cygnus-Lyra regions, between the very bright stars Vega and
Deneb. The photometer will produce light curves, not images, for at
least 100,000 stars simultaneously. It is the equivalent of a
100,000-channel light meter, hence the term photometer.

By searching for a sequence of 'transits' in the light curves from
each star, scientists will determine the planet's orbital period.
From the depth of the 'transit' and knowing the size, mass and
temperature of the star, the team can calculate the planet's size and
the planet's characteristic temperature. Using Kepler's Third Law,
which can be paraphrased as "For circular orbits, the distance of a
planet from its star is proportional to the 2/3 root of the planet's
orbital period," the scientists will be able to calculate the
planet's orbit. The scientists then will be able to determine if the
planet is located in the habitable zone, where liquid water can exist
on the surface of the planet.

Led by the project's principal investigator, William Borucki, and the
project's deputy principal investigator, David Koch, both of NASA
Ames, the science team is comprised of 27 scientists from 15
institutions in the United States, Canada and Denmark.

NASA Ames will manage the photometer contract, while NASA's Jet
Propulsion Laboratory (JPL), Pasadena, Calif., will manage the
spacecraft contract. JPL is responsible for the project's overall
mission development through launch and commissioning. NASA Ames will
manage the mission's operations phase and lead the scientific
analysis and interpretation of data. Ball Aerospace will operate the
spacecraft throughout the mission for NASA.

Scientists expect this mission will detect numerous Earth-size
planets around solar-like stars and hundreds to thousands of planets
of various sizes, in various orbits around a wide variety of stars.

Further details about the Kepler mission can be found at:
http://Kepler.NASA.gov

-end -

Dolores Beasley
Headquarters, Washington Feb. 18, 2005

Nancy Neal Jones
Goddard Space Flight Center, Greenbelt, Md.

RELEASE: 05-051

NASA OBSERVES ONE OF BRIGHTEST COSMIC EXPLOSIONS

Scientists detected a flash of light from across the Galaxy so powerful; it bounced off the moon and lit up the Earth's upper atmosphere. The flash was brighter than anything ever detected from beyond our Solar System, and it lasted over a tenth of a second.

NASA and European satellites and many radio telescopes detected the flash and its aftermath on December 27, 2004. Two science teams are reporting about this event at a special press conference today at 2 p.m. EST at NASA Headquarters, Washington.

NASA's Swift satellite and the National Science Foundation-funded Very Large Array (VLA) were two of many observatories that observed the event arising from neutron star SGR 1806-20. It is a unique neutron star called a magnetar, about 50,000 light years from Earth in the constellation Sagittarius.

The apparent magnitude was brighter than a full moon and all historical star explosions. The light was brightest in the gamma-ray energy range, far more energetic than visible light or X-rays and invisible to our eyes.

"This might be an once-in-a-lifetime event for astronomers, as well as for the neutron star," said Dr. David Palmer of Los Alamos National Laboratory, N.M. He is lead author on a paper describing the Swift observation. "We know of only two other giant flares in the past 35 years, and the December event was 100 times more powerful," he added.

Dr. Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., is lead author on a report describing the VLA observation, which tracked the ejected material as it flew out into interstellar space.

Other key scientific teams are associated with radio telescopes in Australia, The Netherlands, United Kingdom, India and the United States, as well as with NASA's High Energy Solar Spectroscopic Imager (RHESSI).

Neutron stars form from collapsed stars. They are dense, fast-spinning, highly magnetic, and only about 15 miles in diameter. Only about 12 magnetars are known among the millions of regular neutron stars in our Galaxy and neighboring galaxies.

SGR 1806-20 is also a soft gamma repeater (SGR) because it randomly flares and releases gamma rays. Only four SGRs are known. The giant flare on SGR 1806-20 was millions to billions of times more powerful than typical SGR flares. For a tenth of a second, the giant flare unleashed more energy than the sun emits in 150,000 years. Magnetic fields around magnetars are responsible for SGR outbursts, but the details remain unclear.

"The next biggest flare ever seen from any soft gamma repeater was peanuts compared to this incredible December 27 event," Gaensler said. "Had this happened within 10 light years of us, it would have severely damaged our atmosphere. Fortunately, all the magnetars we know of are much farther away than this," he added.

During the 1980s scientists wondered whether gamma-ray bursts were star explosions from beyond our Galaxy or eruptions on nearby neutron stars. By the late 1990s it became clear gamma-ray bursts did indeed originate far away. But the extraordinary giant flare on SGR 1806-20 reopens the debate, according to Dr. Chryssa Kouveliotou of NASA's Marshall Space Flight Center, Huntsville, Ala., who coordinated multiwavelength follow-up observations. A small percentage of short gamma-ray bursts, less than two seconds, could be from SGR flares.

"An answer to the short gamma-ray burst mystery could come any day now that Swift is in orbit", said Swift lead scientist Neil Gehrels.

Scientists around the world have been following the December 27 event. RHESSI detected gamma rays and X-rays from the flare. Drs. Kevin Hurley and Steven Boggs of the University of California, Berkeley, are leading the effort to analyze these data.

For more information about the event on the Internet, visit:

http://www.nasa.gov/vision/universe/watchtheskies/swift_nsu_0205.html

-end-

* * *

First Invisible Galaxy Discovered in Cosmology Breakthrough
By Robert Roy Britt
Senior Science Writer
posted: 23 February 2005
10:44 am ET

Astronomers have discovered an invisible galaxy that could be the first of many that will help unravel one of the universe's greatest mysteries.

The object appears to be made mostly of "dark matter," material of an unknown nature that can't be seen.

Theorists have long said most of the universe is made of dark matter. Its presence is required to explain the extra gravitational force that is observed to hold regular galaxies together and that also binds large clusters of galaxies.

Theorists also believe knots of dark matter were integral to the formation of the first stars and galaxies. In the early universe, dark matter condensed like water droplets on a spider web, the thinking goes. Regular matter -- mostly hydrogen gas -- was gravitationally attracted to a dark matter knot, and when the density became great enough, a star would form, marking the birth of a galaxy.

The theory suggests that pockets of pure dark matter ought to remain sprinkled across the cosmos. In 2001, a team led by Neil Trentham of the University of Cambridge predicted the presence of entire dark galaxies.

One of perhaps many

The newfound dark galaxy was detected with radio telescopes. Similar objects could be very common or very rare, said Robert Minchin of Cardiff University in the UK.

"If they are the missing dark matter halos predicted by galaxy formation simulations but not found in optical surveys, then there could be more dark galaxies than ordinary ones," Minchin told SPACE.com.

In a cluster of galaxies known as Virgo, some 50 million light-years away, Minchin and colleagues looked for radio-wavelength radiation coming from hydrogen gas. They found a well of it that contains a hundred million times the mass of the Sun. It is now named VIRGOHI21.

The well of material rotates too quickly to be explained by the observed amount of gas. Something else must serve as gravitational glue.

"From the speed it is spinning, we realized that VIRGOHI21 was a thousand times more massive than could be accounted for by the observed hydrogen atoms alone," Minchin said. "If it were an ordinary galaxy, then it should be quite bright and would be visible with a good amateur telescope."

The ratio of dark matter to regular matter is at least 500-to-1, which is higher than I would expect in an ordinary galaxy," Minchin said. "However, it is very hard to know what to expect with such a unique object -- it may be that high ratios like this are necessary to keep the gas from collapsing to form stars."

Long road to discovery

Other potential dark galaxies have been found previously, but closer observations revealed stars in the mix. Intense visible-light observations reveal no stars in VIRGOHI21.

The invisible galaxy is thought to lack stars because its density is not high enough to trigger star birth, the astronomers said.

The discovery was made in 2000 with the University of Manchester's Lovell Telescope, and the astronomers have worked since then to verify the work. It was announced today.

"The universe has all sorts of secrets still to reveal to us, but this shows that we are beginning to understand how to look at it in the right way," said astronomer Jon Davies of Cardiff University in the UK. It's a really exciting discovery."
Additional radio observations were made with the Arecibo Observatory in Puerto Rico. Follow-up optical work was done with the Isaac Newton Telescope in La Palma. Astronomers from the UK, France, Italy and Australia contributed to the research. The project is now searching for other possible dark galaxies.

Dark matter makes up about 23 percent of the universe's mass-energy budget. Normal matter, the stuff of stars, planets and people, contributes just 4 percent. The rest of the universe is driven by an even more mysterious thing called dark energy.

Below : The ellipse shows the region of sky where the dark galaxy was found. Credit: Cardiff University/Isaac Newton Telescope on La Palma

I like your Big Spider with black hole feeding tubes analogy Marshall, just as good as any at this point ;o)

Orphan Planets: It's a Hard Knock Life

By Seth Shostak
SETI Institute
posted: 24 February 2005
06:57 am ET
Try to imagine this, a scene unwitnessed by any thinking being, although it could play out every few weeks somewhere in the Milky Way:

You are on the curdled, hot surface of a new-born world; an unknown cousin of Earth only a few millions of years old. The landscape is a sweltering, fulminating jumble of soft rock, as sterile as space itself.

If anyone could gaze at the night sky, they would see a dark bowl riddled with hard, bright dots. The dots are sibling worlds – new planets in various stages of gestation, careening through the viscous disk of gas and lumpy dust that has given them substance and form.

Suddenly, and by chance, a not-so-improbable encounter takes place. The trajectory of another object, a litter mate, crosses nearby. For several days, the second planet sails large across the sky: silent and dangerous.

There is no actual collision; no cataclysmic shattering of nascent worlds. But gravitational interaction during this brief encounter changes the motion of both objects; speeding up one, and slowing the other. And now a dispiriting event unfolds, although this world has no eyes to see it. Ejected by chance from the solar system of its birth, the planet sideslips into deep space. Every hour, the sun that had promised to warm its surface for billions of years recedes by another fifty thousand miles. In a mere decade, the home star shrinks to a point of light, eventually indistinguishable from other stars of the sky. The planet’s surface cools, its atmosphere condenses, falls, and piles up in frozen drifts. This is an orphan world, wandering without destination in the numbing, frigid desert of deep space.

Although it was kicked from the litter by accident, this planet’s involuntary exile may be a frequent fate for newborn worlds. Doug Lin, an astronomer at the University of California at Santa Cruz, says, "My sense is that orphan planets could be numerous. There’s already indirect evidence that Jupiter-sized worlds have been ejected from some of the extrasolar planetary systems we’ve discovered in the last decade. The clue is that large planets in these systems often have highly elliptical orbits." Giant worlds in egg-shaped orbits are, presumably, the objects that were left behind when a planetary fender-bender took place.

"You don’t have that situation in our solar system. We’re lucky because Jupiter – which had a low-eccentricity orbit to begin with – has nudged the other planets into similar near-circular orbits, where they don’t get in one another’s way," notes Lin.

But imagine a system in which no Jupiter-sized planet forms, simply because of a shortage of raw material. Even in this case, there still might be sufficient resources to construct Earth-size and smaller worlds. Some of these will inevitably form at distances between 0.5 to 1 billion miles from the star (the range of orbits staked out by Jupiter and Saturn in our own solar system). At those distances, the orbital velocities are roughly 10 miles per second. That’s slow enough that a gravitational encounter can easily add the 4 additional miles per second that would firmly evict a relatively heavy object from the star system. (For the numerically minded, escape velocities are 41% higher than orbital velocities.)

How often does this happen? "I don’t know what fraction of planets will be tossed out," Lin admits. "But I would imagine the fraction is probably pretty high; in fact I wouldn’t be surprised if it were 50%."

If that’s the case, then orphan planets could be more numerous than stars! In our own galaxy alone, there would be hundreds of billions of these wandering worlds.

That’s a lot of errant real estate, and so the question naturally arises whether there could be life on these Bedouin bodies, given that they might constitute a large fraction of all planetary acreage. At first glance, you might assume there’s not much hope. In deep space, precious little energy is available to either warm an ocean or provide the calories required for metabolism. On Earth, sunlight ultimately fuels most life. Nearly a kilowatt of power impinges on each square yard of the landscape on a sunny day. In interstellar space, where the stars are distant and faint, the energy flux is a billion times less.

Facts are, any surface oceans on an orphan planet will freeze harder than a granite countertop, and photosynthesis will be a non-starter. But bear in mind that life on Earth may have originated from – and certainly still exists in – the superheated waters of deep ocean vents. The muddy water that spews from these sizzling fissures is brought to a boil by heat from the interior – heat that is mostly left over from Earth’s birth. After more than four billion years, our planet is still warm inside. Mars, a smaller world, has largely cooled. There are no moving plates or active volcanoes on the Red Planet. It’s chilled out.

But clearly, for the bulkier orphan planets – those that might be Earth-sized or larger – underground energy for supporting life would last for billions of years. So you can well imagine that while the surface of any oceans on these worlds would be solid ice, biology might still thrive in liquid water below. And after all, you don’t need a lot of warmth. Magma’s not required, merely hot water. As Lin comments, "Melting rocks takes a lot of heat. But for life, all you need do is boil water."

Life on orphan worlds is possible, in other words. But could complex, or even intelligent life arise there? That’s clearly more of a long shot. Frankly, it seems unlikely that life dependent on leakage heat from a planet’s interior would ever become elaborate enough to understand the universe.

Nonetheless, this is a type of habitat that, while possibly quite common, is very alien to our own experience. We cannot say for certain that intelligent life is impossible on these worlds. If such an extravagant development occurs, it would be interesting to know what the inhabitants think about the possibility of life on a planet orbiting a star. Indeed, from their point of view, our home could seem thoroughly unattractive. They might doubt the desirability of living desperately close to a roiling ball of incandescent gas, one that routinely spouts deadly radiation from its stormy countenance. Maybe it’s better to be safely ensconced on a world where the sun never shines.

Dolores Beasley
Headquarters, Washington March 1, 2005

Whitney Clavin
Jet Propulsion Laboratory, Pasadena, Calif.

RELEASE: 05-060

NASA'S SPITZER SPACE TELESCOPE EXPOSES DUSTY GALACTIC HIDEOUTS

How do you hide something as big and bright as a galaxy? You smother it in cosmic dust. NASA's Spitzer Space Telescope saw through the cosmic dust to uncover a hidden population of monstrously bright galaxies approximately 11 billion light-years away.

These strange galaxies are among the most luminous in the universe, shining with the equivalent light of 10 trillion suns. But, they are so far away and so drenched in dust, it took Spitzer's highly sensitive infrared eyes to find them.

"We are seeing galaxies that are essentially invisible," said Dr. Dan Weedman of Cornell University, Ithaca, N.Y., co-author of the study detailing the discovery. It will be published in today's issue of the Astrophysical Journal Letters. "Past infrared missions hinted at the presence of similarly dusty galaxies over 20 years ago, but those galaxies were closer. We had to wait for Spitzer to peer far enough into the distant universe to find these," he said.

Where is all this dust coming from? The answer is not quite clear. Dust is churned out by stars, but it is not known how the dust wound up sprinkled all around the galaxies. Another mystery is the exceptional brightness of the galaxies. Astronomers speculate a new breed of unusually dusty quasars, the most luminous objects in the universe, may be lurking inside. Quasars, like giant light bulbs at the centers of galaxies, are powered by huge black holes.

Another question astronomers would like to address is whether dusty, bright galaxies like these eventually evolve into fainter, less murky ones like our own Milky Way. "It's possible stars like our sun grew up in dustier, brighter neighborhoods, but we really don't know. By studying these galaxies, we'll get a better idea of our own galaxy's history," said Cornell's Dr. James Houck, lead author of the study.

The Cornell-led team first scanned a portion of the night sky for signs of invisible galaxies using an instrument onboard Spitzer called the multiband imaging photometer. The team compared the thousands of galaxies seen in this infrared data to the deepest available ground-based optical images of the same region, obtained by the National Optical Astronomy Observatory Deep Wide-Field Survey. This led to the identification of 31 galaxies that can be seen only by Spitzer. "This large area took us many months to survey from the ground," said Dr. Buell Jannuzi, co-principal investigator for the Deep Wide-Field Survey, "so the dusty galaxies Spitzer found truly are needles in a cosmic haystack."

Further observations using Spitzer's infrared spectrograph revealed the presence of silicate dust in 17 of these 31 galaxies. This particular dust grain is significant, because it is a planetary building block, and it also helped astronomers determine how far away the galaxies are from Earth. Silicates are sand-like planetary building blocks.

"This is the furthest back in time silicate dust has been detected around a galaxy. Finding silicate dust at this very early epoch is important for understanding when planetary systems like our own arose in the evolution of galaxies," said Dr. Thomas Soifer, study co-author and director of the Spitzer Science Center, Pasadena, Calif. "We can break apart the light from a distant galaxy using a spectrograph, but only if we see a recognizable signature from a mineral like silicate, can we figure out the distance to that galaxy," Soifer said.

In this case, the galaxies were dated back to a time when the universe was only three billion years old, or one-quarter of its present age of 13.5 billion years. Galaxies similar to these in dustiness, but much closer to Earth, were first alluded to in 1983 via observations made by the joint NASA-European Infrared Astronomical Satellite. Later, the European Space Agency's Infrared Space Observatory faintly recorded comparable, nearby objects. It took Spitzer's improved sensitivity, 100 times greater than past missions, to finally seek out the dusty galaxies at great distances.

The National Optical Astronomy Observatory Deep Wide-Field Survey used the National Science Foundation's 13-foot telescope at Kitt Peak National Observatory southwest of Tucson, Ariz.

NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center. JPL is a division of Caltech.

Artist's conceptions, images and additional information about the Spitzer Space Telescope are available at: http://www.spitzer.caltech.edu.

-end-

* * *

Huge Space Clouds May Have Caused Mass Extinctions
By Robert Roy Britt
Senior Science Writer
posted: 03 March 2005
08:53 pm ET

Giant space clouds of gas may have changed the climate or atmosphere on Earth and fueled mass extinctions millions of years ago, scientists said Thursday.

In one scenario, the solar system passed through a dense cloud of interstellar material, causing Earth to ice over. In the other, the solar system passed through less dense clouds that destroyed the planet's protective ozone layer, raising levels of harmful ultraviolet radiation.

The possibilities, based on modeling but not yet supported by solid evidence, were presented in the journal Geophysical Research Letters.

Mass extinctions have occurred in Earth's past. That much is clear, from the fossil record. But what cause them is less certain. A widespread die-off 65 million years ago, which wiped out the dinosaurs and many other species, is thought by most scientists to have been caused by an asteroid impact.

Other extinctions have been attributed to impacts, climate change, cosmic rays, exploding stars, increased volcanic activity and even global warming. Multiple events may have conspired to make life difficult in any one of the five known worst mass extinctions.

The idea that we pass through clouds of galactic debris is not new. In fact, a 2003 study found that we're traveling through a mild one right now.

How would space clouds trigger death?

"Computer models show dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense space cloud," said Alex Pavlov, principal author of both papers and a researcher at the University of Colorado, Boulder.

The dust layer would hover around Earth, reducing the amount of sunlight reaching the planet while letting terrestrial heat escape into space, creating a snowballing chill.

"There are indications from 600 to 800 million years ago that at least two of four glaciations were snowball glaciations," Pavlov said. "The big mystery revolves around how they are triggered."

Moderately dense space clouds, the sort that might destroy the ozone layer, are huge, Pavlov points out, and the solar system could take up to 500,000 years pass through one. Extra cosmic rays produced during such an event, owing to interactions of the interstellar dust with the Sun, would break up nitrogen molecules in Earth's atmosphere, leading to ozone destruction.

Pavlov said the work, supported by NASA, might be testable. Geologists could look for higher amounts of uranium 235 in soil layers corresponding to the time of known glaciations. Uranium 235 can't be produced naturally in the solar system.

Gretchen Cook-Anderson
Headquarters, Washington March 8, 2005

Bill Steigerwald
Goddard Space Flight Center, Greenbelt, Md

RELEASE: 05-070

NASA FINDS LIGHTNING CLEARS SAFE ZONE IN EARTH'S RADIATION
BELT

Lightning in clouds, only a few miles above the ground,
clears a safe zone in the radiation belts thousands of miles
above the Earth, according to NASA-funded researchers. The
unexpected result resolves a forty-year-old debate as to how
the safe zone is formed, and it illuminates how the region is
cleared after it is filled with radiation during magnetic
storms.

The safe zone, called the Van Allen Belt slot, is a potential
haven offering reduced radiation dosages for satellites that
require Middle Earth Orbits (MEOs). The research may
eventually be applied to remove radiation belts around the
Earth and other worlds, reducing the hazards of the space
environment.

"The multi-billion-dollar Global Positioning System
satellites skirt the edge of the safe zone," said Dr. James
Green of NASA's Goddard Space Flight Center, Greenbelt, Md.
He is the lead author of the paper about the research
published in the Journal of Geophysical Research. "Without
the cleansing effect from lightning, there would be just one
big radiation belt, with no easily accessible place to put
satellites," he said.

If the Van Allen radiation belts were visible from space,
they would resemble a pair of donuts around the Earth, one
inside the other, with the planet in the hole of the
innermost. The Van Allen Belt slot would appear as a space
between the inner and outer donut. The belts are comprised of
high-speed electrically charged particles (electrons and
atomic nuclei) trapped in the Earth's magnetic field. The
Earth's magnetic field has invisible lines of magnetic force
emerging from the South Polar Region, out into space and back
into the North Polar Region. Because the radiation belt
particles are electrically charged, they respond to magnetic
forces. The particles spiral around the Earth's magnetic
field lines, bouncing from pole to pole where the planet's
magnetic field is concentrated.

Scientists debated two theories to explain how the safe zone
was cleared. The prominent theory stated radio waves from
space, generated by turbulence in the zone, cleared it. An
alternate theory, confirmed by this research, stated radio
waves generated by lightning were responsible. "We were
fascinated to discover evidence that strongly supported the
lightning theory, because we usually think about how the
space environment affects the Earth, not the reverse," Green
said.

The flash we see from lightning is just part of the total
radiation it produces. Lightning also generates radio waves.
In the same way visible light is bent by a prism, these radio
waves are bent by electrically charged gas trapped in the
Earth's magnetic field. That causes the waves to flow out
into space along the Earth's magnetic field lines.

According to the lightning theory, radio waves clear the safe
zone by interacting with the radiation belt particles,
removing a little of their energy and changing their
direction. This lowers the mirror point, the place above the
polar regions where the particles bounce. Eventually, the
mirror point becomes so low; it is in the Earth's atmosphere.
When this happens, the radiation belt particles can no longer
bounce back into space, because they collide with atmospheric
particles and dissipate their energy.

To confirm the theory, the team used a global map of
lightning activity made with the Micro Lab 1 spacecraft. They
used radio wave data from the Radio Plasma Imager on the
Imager for Magnetopause to Aurora Global Exploration (IMAGE)
spacecraft, combined with archival data from the Dynamics
Explorer spacecraft. IMAGE and Dynamics Explorer showed the
radio wave activity in the safe zone closely followed
terrestrial lightning patterns observed by Micro Lab 1.

According to the team, there would not be a correlation if
the radio waves came from space instead of Earth. They
concluded when magnetic storms, caused by violent solar
activity, inject a new supply of high-speed particles into
the safe zone, lightning clears them away in a few days.
Engineers may eventually design spacecraft to generate radio
waves at the correct frequency and location to clear
radiation belts around other planets. This could be useful
for human exploration of interesting bodies like Jupiter's
moon Europa, which orbits within the giant planet's intense
radiation belt.

The research team included Drs. Scott Boardsen, Leonard
Garcia, William Taylor, and Shing Fung from Goddard; and Dr.
Bodo Reinisch, University of Massachusetts, Lowell. For
images and information about this research on the Web, visit:

http://www.nasa.gov/vision/universe/solarsystem/image_lightning.html

-end-

* * *

New observations reveal that the early universe had its own version of rock-and-roll stars – galaxies that grew fast and died young. What killed these up-and-comers is not yet known.

Using the Spitzer Space Telescope, Ivo Labbé of Carnegie Observatories and his colleagues studied about a dozen massive galaxies shining two billion years after the Big Bang – when the universe was less than a fifth of its present age.

The galaxies, which typically had about 100 billion stars, constitute a variety of different types: some forming new stars, some clouded by dust, and some quite dead in terms of their ability to make new stars.

"It's becoming more and more clear that the young universe was a big zoo with animals of all sorts," said Labbé, lead author of the study. "There's as much variety in the early universe as we see around us today."

The most surprising of these animals are the dead galaxies that literally ran out of gas – or at least cold gas – for making new stars. These giants suffocated far sooner than expected.

"We are really amazed – these are the earliest, oldest galaxies found to date," Labbé said. "Their existence was not predicted by theory and it pushes back the formation epoch of some of the most massive galaxies we see today."

There are observations of even earlier galaxies – from less than a billion years after the Big Bang, but the data are not good enough to tell what exactly was going on inside them, said co-author Jiasheng Huangat of the Harvard-Smithsonian Center for Astrophysics.

Color-coding

Astronomers can tell the "liveliness" of a galaxy by its color. Galaxies with ongoing star formation are bluer because of the hot massive stars that shine the brightest. Older galaxies appear redder because massive stars burn out first – leaving only the smaller, cooler stars.

"The current theory would say that most [early] galaxies would be blue," Huangat told Space.com in a telephone interview.

This is why Huangat and his colleagues were interested in looking at red galaxies seen in the Hubble Deep Field South – one of the space telescope’s penetrating views into the early universe.

Besides early retirement, these Hubble-detected galaxies could appear red because they are full of dust, which absorbs blue light more than red. With Spitzer’s infrared camera, Labbé and his team determined that 75 percent of the red galaxies were indeed dusty.

The rest, though, had stopped forming new stars for about a billion years. Labbé said that it is rare for galaxies to go that long without any star formation.

"Galaxies form stars," he said. "That is what they do."

Galaxy killers

According to Labbé, no one is certain how these early galaxies petered out. They could be so massive that the gas inside became too hot to collapse into new stars. But this galaxy death is thought to happen when the universe is much older.

Labbé thinks a more plausible mechanism is that a super-massive black hole in the center of these dead galaxies is swallowing up gas and spewing out jets and radiation in a way that disrupts star formation in the rest of the galaxy.

Such violent super-massive black holes are typically seen as bright quasars, or more generally active galactic nuclei (AGN). The astronomers plan in future observations to look for evidence of AGN in their dead galaxies.

Dead but not gone

Just because these early galaxies are "deceased," it does not mean they disappeared. Their small red stars continued to shine for billions of years. In fact, some of the galaxies around us today must have long ago looked dead. But which ones?

If you started with one of the galaxies seen in this study, and then ran the clock forward 12 billion years to the present day, the galaxy would be more massive and look "even more dead," Huangat said. Nowadays, the big and very red (dead) galaxies are the giant ellipticals.

"It is very likely that these dead galaxies evolve into massive giant ellipticals," Labbé said.

But there are more giant ellipticals than there were dead galaxies, so multiple avenues must exist for making giant ellipticals, Labbé explained.

This article is part of SPACE.com's weekly Mystery Monday series.

Headquarters, Washington March 25, 2005

D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.

RELEASE: 05-086

NASA RELEASES DEEP IMPACT MISSION STATUS REPORT

NASA's Deep Impact spacecraft completed the commissioning phase of the mission and has moved into the cruise phase.

Deep Impact mission planners have separated the spacecraft's flight operations into five mission phases. Cruise phase will continue until about 60 days before the encounter with comet Tempel 1 on July 4, 2005.

Soon after launch on Jan. 12, 2005, Deep Impact entered the commissioning phase. During that phase, the mission team verified the basic state of health of all subsystems and tested the operation of science instruments. The spacecraft's autonomous navigation system was activated and tested using the moon and Jupiter as targets.

The spacecraft's high gain antenna, which will relay images and data of the cometary collision, was activated and is operating properly. A trajectory correction maneuver was performed, refining the spacecraft's flight path to comet Tempel 1. The maneuver was so successful that a second one planned for March 31 was cancelled.

Another event during commissioning phase was the bake-out heating of the spacecraft's High Resolution Instrument (HRI) to remove normal residual moisture from its barrel. The moisture was a result of absorption into the structure of the instrument during the vehicle's last hours on the launch pad and its transit through the atmosphere to space.

At completion of the bake-out procedure, test images were taken through the HRI. These images indicate the telescope has not reached perfect focus. A special team has been formed to investigate the performance and to evaluate activities to bring the telescope the rest of the way to focus. Future calibration tests will provide additional information about the instruments' performance.

The Deep Impact spacecraft has four data collectors to observe the effects of the collision: a camera and infrared spectrometer comprise the High Resolution Instrument; a Medium Resolution Instrument (MRI); and a duplicate camera on the Impactor Targeting Sensor (ITS). They will record the vehicle's final moments before it is run over by comet Tempel 1 at approximately 23,000 mph. The MRI and ITS are performing as expected.

"This in no way will affect our ability to impact the comet on July 4," said Rick Grammier, Deep Impact project manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. "Everyone on the science and engineering teams is getting very excited and looking forward to the encounter."

Dr. Michael A'Hearn of the University of Maryland, College Park, Md., added, "We are very early in the process of examining the data from all the instruments. It appears our infrared spectrometer is performing spectacularly, and even if the spatial resolution of the High Resolution Instrument remains at present levels, we still expect to obtain the best, most detailed pictures of a comet ever taken."

Deep Impact is comprised of two parts, a flyby spacecraft and a smaller impactor. The impactor will be released into the comet's path for the planned high-speed collision. The crater produced by the impactor is expected to range from the width of a house up to the size of a football stadium and be from two to 14 stories deep. Ice and dust debris will be ejected from the crater revealing the material beneath.

Along with the imagers aboard the spacecraft, NASA's Hubble, Spitzer and Chandra space telescopes, along with the largest telescopes on Earth, will observe the effects of the material flying from the comet's newly formed crater.

An intimate glimpse beneath the surface of a comet, where material and debris from the formation of the solar system remain relatively unchanged, will answer basic questions about the formation of the solar system. The effects of the collision will offer a better look at the nature and composition of these celestial travelers.

The University of Maryland provides overall mission management for this Discovery class program. Project management is handled by JPL. The spacecraft was built for NASA by Ball Aerospace & Technologies Corporation, Boulder, Colo.

For more information about Deep Impact on the Internet, visit:

http://www.nasa.gov/deepimpact

For more information about NASA on the Internet, visit:

http://www.nasa.gov
-end-

* * *

Habitable Planets: Disaster Zones and Safe Havens

By Robert Roy Britt
Senior Science Writer
posted: 05 April 2005
06:22 am ET

New computer simulations of known extrasolar planetary systems suggest about half of them could harbor an Earth-like world, mathematically speaking.

All of the known planets orbiting other Sun-like stars -- there are at least 130 -- are very massive, most similar in heft to Jupiter. Earth-sized planets, if any exist, can't be found with present technology (with the exception of a handful discovered around a dying star). But several models by different groups have shown rocky planets about the size of Earth could exist in known systems where a giant planet orbits a Sun-like star.

In the new work, researchers created hypothetical giant planets and found that each creates two disaster zones -- one inside its orbit (closer to the star) and one outside. A fledgling Earth in either zone will either be lured into a collision with the larger planet, will hit the star, or will be tossed out to the cold, dead, far suburbs of the system.

That's no surprise. But the specifics of the model bear attention: The disaster zones are governed by the giant planet's mass and the eccentricity of its orbit, or how noncircular it is.

"The larger its orbital eccentricity, the greater the gravitational reach of the giant," said Barrie Jones, an astronomy professor at the Open University in the UK.

The question was this: What sort of system with a large planet can support a rocky planet in a habitable zone, the region where temperatures are favorable for allowing liquid water to exist on an Earth-sized planet.

"If liquid water can exist, so could life as we know it," Jones said.

Other researchers caution that the presence of water does not mean life necessarily exists. Nobody knows how life begins or whether it has gotten started anywhere beyond Earth. But rocky, wet planets are a great place to start looking for biological activity.

To allow an Earth-sized planet in a stable orbit within a habitable zone, the giant must either be well outside that zone, as Jupiter and the other giants are in our solar system, or well inside, the modeling found.

"The more massive the giants the further their perturbing gravitational reach, and the more distant from the habitable zone they need to be," Jones told SPACE.com. "You can't be too near a giant or its gravity will wreak havoc with the 'Earth' orbit."

This is where the modeling gets interesting.

The scientists then applied these rules to real planetary systems. Several of the known extrasolar setups involve a "hot Jupiter," a planet roughly the mass of Jupiter in a very tight orbit around its star. These worlds see a year go by in less than a week.

The computer-generated disaster zones, particular to each actual star and its giant planet, were compared to that star's habitable zone to see if there were any safe havens -- stable orbital routes within habitable zones.

When the computer model was run, about half of the known systems allowed a safe haven over a long enough time period, including into the present, to possibly allow life to evolve, the researchers found.

A few other systems had habitable zones in the past or will have them in the future as their stars age and energy outputs change. Toss these in and the researchers come up with about two-thirds of the 130 systems they studied harboring habitable zones at some time in the past, present or future.

The research was to be presented today at the National Astronomy Meeting of the Royal Astronomical Society. Open University researchers Nick Sleep and David Underwood contributed to the work.

Scientists do not expect to discover Earth-sized planets until a new generation of space telescopes, such as NASA's Kepler mission, fly later in this decade.

BOULDER, Colorado – Consider it nothing short of the cosmic quest for all time: Understanding the origin, evolution, distribution, and fate of life on Earth and in the Universe.

That’s a tall order…but within the sights of experts gathering here this week to take part in the 2005 Biennial Meeting of the NASA Astrobiology Institute.

From the formation and evolution of habitable worlds to the origins of life, extra-solar planets, and future exploration technologies and strategies – dedicated scientists are tackling big questions in a big universe.

Unanswered questions

There has been a salvo of new findings, just within the last few years alone.

Planet detection outside our solar system is on the upswing. The Huygens robot lander plopped down on Titan, a moon of Saturn. And information continues to stream in from the Mars rovers, Spirit and Opportunity.

"Everything is accelerating…and astrobiology knowledge is accelerating too," said Bruce Runnegar, Director of the NASA Astrobiology Institute (NAI), an international research consortium with central offices located at NASA Ames Research Center in the heart of California’s Silicon Valley. "It’s a wonderful time to be alive, but it is hard to deal with because there are so many new discoveries and so much data," he told SPACE.com.

Runnegar said the field of astrobiology makes use of "multidisciplinarians" – individuals capable of cutting across and building bridges between disciplines.

NASA’s visionary Moon, Mars and beyond is a major thrust, one that embraces astrobiology, Runnegar said.

"Astrobiology is important not only for those space exploration goals but also for understanding how we can take life from here elsewhere…and what we should do with humanity as we move out into space. It’s central to the vision," Runnegar added.

There are unanswered questions about our place in the Universe, as well as interest in exploring new territories and new worlds, Runnegar said. "Both of those things, I think, are going to ultimately drive the exploration vision."

Scientists plugging away

The NAI is currently composed of 16 lead teams, which together represent over 700 investigators across the United States. In addition, the NAI has international partnerships with astrobiology research organizations around the world.

David Morrison, NAI’s senior scientist, said astrobiology is a growing field. Some of the leading research can be tied to events like the exploration of Mars with the rovers, "but a lot of it is just individual scientists plugging away," he said.

"Most of it is not predictable," Morrison said, although planting an astrobiology science rover on Mars either in 2009 or 2011 is hopefully in the plans. Furthermore, he pointed to the Kepler Mission to be launched within the next few years. This spacecraft, for the first time, will search our galaxy for Earth-size or even smaller planets.

"I can’t predict what will be discovered in the coming years…but I think it’s going to be exciting," Morrison said.

Earth look-alikes?

The growing roster of planets found outside our solar system has shored up the prospect for "a whole lot of life" out there," said Jill Tarter, Director of The Center for the Study of Life in the Universe at the SETI Institute in Mountain View, California.

"What a fabulous opportunity to think about the boundaries of what that life might be like," Tarter said. "The planets are there. We can’t deny that anymore. It’s really setting the backdrop and driving forward everybody’s thinking. So it just gets more exciting to think about how nature might have generalized biology and geology," she said.

Tarter also pointed to the Kepler mission and its future scouting for Earth-like planets. "This decade we’re going to be able to tell you something about the demographics of terrestrial planets. Either they are prevalent or they are very rare. But this is the decade to get those data," she said.

There will be a capability of getting that answer, agreed Nick Woolf, an astronomer at the University of Arizona in Tucson. But he’s not ready to sign up for lots of Earth look-alikes out there.

"I started off expecting Earth-like planets to be very common…and have become steadily more cautious," Woolf advised. "That does not mean that my change of opinion is correct. I believe that the attitude we should adopt at the present is agnostic."

Researchers have identified what may be the perfect place for a Moon base, a crater rim near the lunar north pole that's in near-constant sunlight yet not far from suspected stores of water ice.

Permanently sunlit areas would provide crucial solar energy for any future Moon settlement, a goal for NASA outlined last year by President George W. Bush. Such sites would also have resort-like temperatures compared with other lunar locations that fluctuate between blistering heat and unfathomable cold.

Equally important, in the permanently shadowed depths of craters around the lunar north pole, water ice may lurk, according to previous but unconfirmed observations.

Melted, it would be vital for drinking. Broken into hydrogen and oxygen, the water could provide breathable air and be used to make rocket fuel for a trip to Mars.

That fits in neatly with the White House vision of using the Moon as a stepping stone to Mars.

Hot real estate

The best spot to settle on the Moon may be on the northern rim of Peary crater, close to the north pole, says Ben Bussey of Johns Hopkins University. The analysis, to be published in the April 14 issue of the journal Nature, is based on 53 images from the spacecraft Clementine, which orbited the Moon for 71 days in 1994.

THE MOON
Unlike Earth, whose extreme tilt causes seasons, the Moon's rotational axis is almost perfectly upright, deviating just 1.5 percent from the main plane of the solar system that extends outward from the Sun's belly. On Earth, summer means constant sunlight at the North Pole, and winter plunges the Arctic into permanent darkness. But on the Moon, theorists have long suspected there might be high points from which the Sun is always visible.

Because the Moon has virtually no atmosphere, temperature fluctuate wildly from day to night, from about 212 degrees Fahrenheit (100 Celsius) to minus 292 Fahrenheit (-180 Celsius) near the equator.

Other scientists have estimated that temperatures on any possible permanently lit spot would be comparatively balmy, though still a frigid minus 58 Fahrenheit (-50 Celsius), give or take a little.

"A region with this relatively benign temperature range represents an attractive site for building hardware designed for long-term use," Bussey and his colleagues write.

The researchers produced an illumination map of the polar region. The Peary crater, created long ago by the impact of an asteroid, is about 45 miles (73 kilometers) wide.

Questions remain

Craters near the south pole have also been previously discussed for a possible Moon base. Those are not highlighted by any constantly illuminated spots, the same research group concluded previously. Even so, the north polar region needs further analysis before NASA can decide where to go first.

Clementine was in a position to see the lunar north pole for only brief periods of the northern summer. So Bussey's team had had to make assumptions about the extent of winter sunlight.

"With the information available, it is not possible to state definitively that these areas are permanently sunlit because the data correspond to a summer rather than a winter day," the scientists report. "But we can be certain that they are the most illuminated regions around the north pole and that they are also the areas on the Moon most likely to be permanently sunlit, given that there are no constantly illuminated areas in the south polar region."

MOON BASE
The south polar sites are not ruled out, however, since sunlight is no more important than water.

"It's a combination of those two things that determines which pole you'll visit first," Bussey said in a telephone interview.

The European Space Agency's SMART-1 craft, currently orbiting the Moon, is expected to shed additional light on lunar topography. NASA plans a robotic reconnaissance effort in 2008 that would provide more information on polar illumination. Meanwhile, India's first mission to the Moon, planned for 2007, would pack a U.S.-made radar instrument designed to pin down the locations of water ice.

Bussey said water ice might be found to be equally distributed at both poles, or it may exist only in select craters.

Steve Roy
Marshall Space Flight Center, Huntsville, Ala.

Megan Watzke
Chandra X-ray Center, Cambridge, Mass.

RELEASE: 05-120

NASA'S CHANDRA OBSERVATORY CATCHES X-RAY SUPER-FLARES

New results from NASA's Chandra X-ray Observatory about the Orion Nebula imply super-flares torched our young solar system. Such X-ray flares likely affected the planet-forming disk around the early sun, and may have enhanced the survival chances of Earth.

By focusing on the Orion Nebula almost continuously for 13 days, a team of scientists used Chandra to obtain the deepest X-ray observations ever taken of any star cluster. The Orion Nebula is the nearest rich stellar nursery, located just 1,500 light years away from Earth.

The Orion Nebula provides an unparalleled view of 1,400 young stars, 30 of which are prototypes of the early sun. Scientists have discovered these young stars erupt in enormous flares that dwarf, in energy, size and frequency, anything seen from our sun today.

"We don't have a time machine to see how the young sun behaved, but the next best thing is to observe sun-like stars in Orion," said Scott Wolk of Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "We are getting a unique look at stars between one and 10 million years old - a time when planets form."

A key finding is the more violent stars produce flares one hundred times as energetic as the more docile ones. This difference may specifically affect the fate of planets that are relatively small and rocky, like the Earth.

"Big X-ray flares could lead to planetary systems like ours, where Earth is a safe distance from the sun," said Eric Feigelson of Penn State University in University Park. He is the principal investigator for the international Chandra Orion Ultradeep Project. "Stars with smaller flares, on the other hand, might end up with Earth-like planets plummeting into the star."

According to recent theoretical work, X-ray flares can create turbulence when they strike planet-forming disks, and this affects the position of rocky planets as they form. Specifically, this turbulence can help prevent planets from rapidly migrating towards the young star.

"Although these flares may be creating havoc in the disks, they ultimately could do more good than harm," said Feigelson. "These flares may be acting like a planetary protection program."

About half of the young suns in Orion show evidence of planet-forming disks including four lying at the center of proplyds (proto-planetary disks) imaged by NASA's Hubble Space Telescope. X-ray flares bombard these disks, likely giving them an electric charge. This charge, combined with motion of the disk and the effects of magnetic fields, should create turbulence in the disk.

The numerous results from the Chandra Orion Ultradeep Project will appear in an upcoming issue of The Astrophysical Journal Supplement. The team contains 37 scientists from institutions in the U.S., Italy, France, Germany, Taiwan, Japan and the Netherlands.

NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. Northrop Grumman, Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Additional information and images pertaining to this research is available at:

http://chandra.harvard.edu
& http://chandra.nasa.gov

-end-

* * *

Dolores Beasley
Headquarters, Washington May 24, 2005

Rachel Weintraub
Goddard Space Flight Center, Greenbelt, Md.

RELEASE 05-132

SOLAR FIREWORKS SIGNAL NEW SPACE WEATHER MYSTERY

The most intense burst of solar radiation in five decades accompanied a large solar flare on January 20. It shook space weather theory and highlighted the need for new forecasting techniques, according to several presentations at the American Geophysical Union (AGU) meeting this week in New Orleans.

The solar flare, which occurred at 2 a.m. EST, tripped radiation monitors all over the planet and scrambled detectors on spacecraft. The shower of energetic protons came minutes after the first sign of the flare. This flare was an extreme example of the type of radiation storm that arrives too quickly to warn interplanetary astronauts.

"This flare produced the largest solar radiation signal on the ground in nearly 50 years," said Dr. Richard Mewaldt of the California Institute of Technology, Pasadena, Calif. He is a co-investigator on NASA's Advanced Composition Explorer (ACE) spacecraft. "But we were really surprised when we saw how fast the particles reached their peak intensity and arrived at Earth."

Normally it takes two or more hours for a dangerous proton shower to reach maximum intensity at Earth after a solar flare. The particles from the January 20 flare peaked about 15 minutes after the first sign.

"That's important because it's too fast to respond with much warning to astronauts or spacecraft that might be outside Earth's protective magnetosphere," Mewaldt said. "In addition to monitoring the sun, we need to develop the ability to predict flares in advance if we are going to send humans to explore our solar system."

The event shakes the theory about the origin of proton storms at Earth. "Since about 1990, we've believed proton storms at Earth are caused by shock waves in the inner solar system as coronal mass ejections plow through interplanetary space," said Professor Robert Lin of the University of California at Berkeley. He is principal investigator for the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). "But the protons from this event may have come from the sun itself, which is very confusing."

The origin of the protons is imprinted in their energy spectrum, as measured by ACE and other spacecraft, which matches the energy spectrum of gamma-rays thrown off by the flare, as measured by RHESSI. "This is surprising because in the past we believed the protons making gamma-rays at the flare were produced locally and the ones at the Earth were produced instead by shock acceleration in interplanetary space," Lin said. "The similarity of the spectra suggests they are the same."

Solar flares and coronal mass ejections (CMEs), associated giant clouds of plasma in space, are the largest explosions in the solar system. They are caused by the buildup and sudden release of magnetic stress in the solar atmosphere above the giant magnetic poles we see as sunspots. The Transitional Region and Coronal Explorer (TRACE) and the Solar and Heliospheric Observatory (SOHO) spacecraft are devoted to observing the sun and identifying the root causes of flares and CMEs, with an eye toward forecasting them.

"We do not know how to predict the flow of energy into and through these large flares", said Dr. Richard Nightingale of the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alta, Calif. "Instruments like TRACE give us new clues with each event we observe."

TRACE has identified a possible source of the magnetic stress that causes solar flares. The sunspots that give off the very largest (X-class) flares appear to rotate in the days around the flare. "This rotation stretches and twists the magnetic field lines over the sunspots", Nightingale said. "We have seen it before virtually every X-flare that TRACE has observed since it was launched and more than half of all flares in that time."

However, rotating sunspots are not the whole story. The unique flare came at the end of a string of five other very large flares from the same sunspot group, and no one knows why this one produced more sudden high energy particles than the first four.

"It means we really don't understand how the sun works," Lin said. "We need to continue to operate and exploit our fleet of solar-observing spacecraft to identify how it works."

For more information and graphics about this story on the Web, visit:

http://www.nasa.gov/vision/universe/solarsystem/solar_fireworks.html

-end-

* * *

Astronomers announced today the discovery of the smallest planet so far found outside of our solar system. About seven-and-a-half times as massive as Earth, and about twice as wide, this new extrasolar planet may be the first rocky world ever found orbiting a star similar to our own.

"This is the smallest extrasolar planet yet detected and the first of a new class of rocky terrestrial planets," said team member Paul Butler of the Carnegie Institution of Washington. "It's like Earth's bigger cousin."

Currently around 150 extrasolar planets are known, and the number continues to grow. But most of these far-off worlds are large gas giants like Jupiter. Only recently have astronomers started detecting smaller massed objects

"We keep pushing the limits of what we can detect, and we're getting closer and closer to finding Earths," said team member Steven Vogt from the University of California, Santa Cruz.

The discovery of Earth’s distant cousin was announced today at a press conference at the National Science Foundation in Arlington, Va.

The new planet orbits Gliese 876, an M dwarf star 15 light years away in the constellation Aquarius. The "super-Earth" is not alone: there are two other planets – both Jupiter-sized – in the same system. This third world was detected by a tiny extra wobble that it caused in the central star.

From this wobble, the researchers measured a minimum mass for the new planet of 5.9 Earth masses. The planet orbits makes a full orbit in a speedy 1.94 days, implying a distance to the central star of 2 million miles – or about 2 percent of the distance between the Earth and the Sun.

Orbiting so close to its star, scientists speculate that the planet’s temperature is a toasty 400 to 750 degrees Fahrenheit (200 to 400 degrees Celsius). This is likely too hot for the planet to retain much gas, like Jupiter does. Therefore, the planet must be mostly solid.

"The planet's mass could easily hold onto an atmosphere," said Gregory Laughlin from UC Santa Cruz. "It would still be considered a rocky planet, probably with an iron core and a silicon mantle. It could even have a dense steamy water layer."

A paper detailing these results has been submitted to The Astrophysical Journal.

Ingredients for Life Found in Early Universe
By Robert Roy Britt
Senior Science Writer
posted: 28 July 2005
04:01 pm ET

The stuff of burnt toast, auto emissions and life itself has been spotted in galaxies so far away they are seen at a time when our universe was just one-fourth its current age.

The discovery of organic molecules, called hydrocarbons, shows that the raw materials for life were present long before our solar system formed.

Scientists do not know how life made the jump from organic material to biological material, so the finding says nothing about whether there is or ever was life elsewhere in the universe.

The galaxies are about 10 billion light-years away, so they are seen as they existed 10 billion years ago. Earth is 4.5 billion years old, and the universe has been around for about 14 billion years.

A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

"These complex compounds tell us that by the time we see these galaxies, several generations of stars have already been formed," said George Helou of the Spitzer Science Center at the California Institute of Technology in Pasadena, Calif. "Planets and life had very early opportunities to emerge in the universe."

The galaxies were imaged with NASA's Spitzer Space Telescope.

The large molecules, called polycyclic aromatic hydrocarbons, are made of carbon and hydrogen and are considered to be among the building blocks of life. They are common on Earth, forming naturally and also whenever you overcook a burger, drive your car, or somehow otherwise burn carbon-based material.

The hydrocarbons are also found throughout our Milky Way Galaxy. It is not too surprising to find them in more distant places, but scientists until now had not pinned down how early in the universe they formed.

In the leading theory of the universe's development, things were mostly hydrogen at first. As stars formed and died, new and heavier elements were added to the mix, such as oxygen and metals. The soup of the cosmos got more complex with each generation of stars. Somewhere in there, elements combined to form hydrocarbons. Add a little water, stir, and somehow life begins.

The study, to be published in the Aug. 10 issue of the Astrophysical Journal, was led by Lin Yan of the Spitzer Science Center.

The organic compounds were found in galaxies that host intense star formation. The galaxies are nearly invisible in regular light, but Spitzer images the heavens by recording infrared light, which represents heat.

By splitting the infrared light into its spectrum of colors, scientists were able to identify the organics.

By Seth Shostak
Senior Astronomer, SETI Institute
posted: 04 August 2005
06:29 am ET

Many of them are tiny, all of them are tough, and they could be your most distant ancestors.

True to their name (which is a Greco-Latin combo for "someone who loves extremes"), extremophiles can batten and fatten in conditions that humans – and most other species – would consider off limits. The first of these sturdy organisms to be discovered, a thermophile, was found in the late 1960s in Yellowstone National Park, hanging out in one of the hot springs. It was a bacterium with a name bigger than itself: Thermus aquaticus (literally, "warm bath water dweller." Species names are often surprisingly prosaic once you translate them.)

Thermus aquaticus not only withstood, but thrived, in temperatures above 160 F. For comparison, try turning on the hot water tap at home, and let it run. It will scald your hand, but the temperature won’t exceed 140 F. This is observational proof that you are not a thermophile.

As it turns out, Thermus aquaticus is only middle-of-the-road tough when it comes to taking the heat. One hyperthermophile, Pyrolobus fumarii, can tread water at a scalding 235 F. That’s not only above the boiling point, but it will soften the upholstery in your pickup. Other extremophiles operate smoothly in below-freezing cold (psychrophiles), highly acid or base solutions (acidophiles and alkaliphiles), heavy-duty brines (halophiles), and in circumstances of crushing high pressure or dusty dryness (piezophiles and xerophiles). There are varieties that can shrug off nuclear radiation, or dwell well in aviation fuel. Frankly, extremophiles would be recruited for the local SWAT team, if they were big enough to carry weapons.

The Hard Cell

How do they do it? What defenses do these frequently diminutive creatures (many are microbial, although not all - think penguins) mount against environmental conditions that would either pickle or pyrolize you and me? There are two fundamental strategies: erect a barrier against the elements, or change your metabolism.

For example, some halophiles protect themselves from a saline environment by increasing the concentration of salts in their innards. With salinity about the same both within and without the cell, the halophile needn’t fear that runaway osmosis will drain it of its precious water.

If you can’t defend against a brutal habitat, you can learn to love it. For example, psychrophiles come equipped with special proteins to adapt their lifestyle to the cold. Some of these proteins act as antifreeze to lower the freezing point of water, to prevent its congealing, expanding, and sundering the cell. Other proteins (enzymes) are specially formulated to ensure that chemistry continues even when the temperature dips to the single digits or lower.

Many researchers are looking for ways to exploit the Darwinian inventiveness that has produced these extremophile defense mechanisms. For example, Deinococcus radiodurans, which boasts a highly sophisticated DNA repair shop within its tiny cell walls, is able to recover from exposure to massive doses of molecule-busting, high energy radiation by simply fixing the damage. It’s hoped that this talent will prove useful in engineering microbes that can clean up radioactive spills, or possibly even protect us from skin cancer.

Extremophiles in Space

By definition, most of the habitats on Earth are not extreme. Extremophiles are the exception, rather than the rule. And yet when we search the solar system for biology, we expect that if there are alien life-forms nearby, they will most likely be analogs to Earth’s extremophiles. This is simply because, whether you’re talking about aquifers beneath the cold, ultraviolet-stung sands of Mars, or the deep, salty seas of Europa, you’re describing environments as brutal as Green Bay’s defensive line. Most of your local flora and fauna would perish straight-away in these nasty niches. But Earth’s extremophiles – some of them – could be transplanted to such otherworldly habitats and never look back.

The question is less whether survival in the hypothesized ecological recesses of Mars and a few of Jupiter and Saturn’s moons is possible – that seems more than likely – but whether it could arise in the first place. The fact that extremophiles may be our oldest living relatives here on Earth suggests that these highly specialized organisms can appear quickly, and do so in the hellish environments that would exist on many young solar system worlds.

It is, in fact, currently fashionable to argue that life on Earth may have begun, not in Charles Darwin’s "warm little pond," but in a seething, scalding and turbulent sub-ocean geyser, where chemical reactions run fast and hard. This, of course, is a habitat that thermophiles are pleased to call home. In the 1970s, DNA studies revealed that thermophiles branched off early from the tree of life, and that they are as old as any creatures we know. This is obviously compatible with the view that they were the first sort of life to arise. After all, although naturally boiling water is confined to only a few places on Earth today, there was a time, more than 3-1/2 billion years ago, when our planet was laced with seething, sizzling caldrons. The earliest life might well have had to be capable of hanging tough in a tough and sweaty world. Thermophiles might have paved the way for today’s millions of species.

This scenario, while seductive, is not air tight. It’s always possible that life actually arose in more moderate conditions, but nearly all of it was obliterated by a large rock from space. Thermophiles, ensconced near hydrothermal vents miles beneath the sea’s surface and protected from the tragedy above, might have been the only survivors of this unrecorded catastrophe. They might appear to be our earliest relatives only because all their ancestors died without trace.

Such uncertainties are part of the allure of extremophiles for the astrobiologist. Perhaps these hardy types are the prototypes for all subsequent life; perhaps not. But there’s no doubt that they are Nature’s best candidates for a body plan that will work on other worlds that we know. They have engineered their own space suits.

Extremophiles, a biological curiosity here on Earth, could represent the most frequent form of life in the universe. What’s exotic and rare on our planet might be both common and commonplace elsewhere. Indeed, perhaps the "extremophile" appellation is too provincial, and we should really call them Vita vulgaris.

I did marvel at the read, thank you for the updates.

Giant Bubble Bullies Our Space
By Robert Roy Britt
LiveScience Managing Editor
posted: 06 April 2006
06:42 am ET

When stars explode as supernova, they carve giant bubbles in space. Our own solar system is enveloped by such a structure from a long-ago explosion.

Now scientists have shown that our bubble is being pinched and bullied backward by another expanding bubble forged from multiple supernovas.

Our bubble is called the Local Bubble by astronomers. It’s shaped like an hourglass. The bully goes by the name of Loop 1 Superbubble; it’s the result of several exploded stars over the past few million years, researchers figure.

Superbubble’s outer boundaries are marked by hot, expanding gas that radiates low-energy X-rays.

Superbubble is expanding faster than Local Bubble, so it compresses an area of cool dense gas, known as the Wall, situated between the two shells. In fact, the new study concludes, this interaction is what gives our bubble the waist in its hourglass shape.

The observation was made with the European Space Agency’s XMM-Newton Space Telescope. It wasn’t easy.

"The X-ray radiation from the bubbles is very faint. In order to see them, we’ve had to remove all the light from stars, nebulae and cosmic rays the images, leaving only the weak X-ray signal," said University of Leicester researcher Michelle Supper, who presented the results yesterday the National Astronomy Meeting of the Royal Astronomical Society. "It’s the astronomical equivalent of looking at an aquarium, ignoring the fish and looking only at the water."

The density of gas in the waist of the hourglass is four times more intense than elsewhere along the Wall. Pressure also peaks there.

From where we sit, the edge of the Local Bubble is at least 91 light-years away in one direction and 358 light-years in the opposite. Superbubble is 895 light-years across. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

This composite X-ray (blue)/radio (pink) image of the galaxy cluster Abell 400 shows radio jets immersed in a vast cloud of multimillion degree X-ray emitting gas that pervades the cluster. The jets emanate from the vicinity of two supermassive black holes (bright spots in the image). Credit: X-ray: NASA/CXC/AIfA/D.Hudson & T.Reiprich et al.; Radio: NRAO/VLA/NRL

Two supermassive black holes have been found to be spiraling toward a merger, astronomers said today.

The collision will create a single super-supermassive black hole capable of swallowing material equal to billions of stars, the researchers said.

Mergers between black holes are thought to be one way they grow. A handful of similar setups have been observed in which black holes appear inevitably on a merger course. This pair, at the center of a galaxy cluster called Abell 400, was known to be close but their fate hadn't been determined.

"The question was: Is this pair of supermassive black holes an old married couple, or just strangers passing in the night?" said Craig Sarazin of the University of Virginia. "We now know that they are coupled, but more like the mating of black widow spiders. One of the black holes invariably will eat the other."

Black holes can't be seen. Their presence is inferred by their gravitational effects on their surroundings and by radiation from near the black hole, where a feeding frenzy superheats gas so much that it emits X-rays.

Determining that these two black holes will collide involved other indirect evidence, drawing data from NASA's Chandra X-ray Observatory.

Each of the black holes in Abell 400 is ejecting a pair of oppositely directed jets of superheated gas called plasma. The movement of the black holes through gas in the galaxy cluster causes the plasma jets to be swept backward.

"The jets are similar to the contrails produced by planes as they fly through the air on Earth," Sarazin said. "From the contrails, we can determine where the planes have been, and in which direction they are going. What we see is that the jets are bent together and intertwined, which indicates that the pair of supermassive black holes are bound and moving together."

When the objects merge several million years from now, Einstein's theory of relativity predicts they will emit a burst of gravitational waves. Similar mergers could soon be detected by NASA's planned Laser Interferometer Space Antenna (LISA).

Hot Discovery: Dark Vortex on Venus
By Sara Goudarzi
Staff Writer
posted: 13 April 2006
01:11 pm ET

The latest images from Venus show a previously suspected dark vortex over the south pole of the planet.

Sending the first ever images of this planet's south pole, the European Space Agency's (ESA) Venus Express mission shows the unexplained formation from a distance of 128,283 miles (206,452 kilometers).

The vortex corresponds to a similar cloud structure over the north pole of the planet.

"Just one day after arrival, we are already experiencing the hot, dynamic environment of Venus," said Hakan Svedhem, Venus Express project scientist. "We will see much more detail at an unprecedented level as we get over 100 times better resolution as we get closer to Venus, and we expect to see these spiral structures evolve very quickly."

After five months of spaceflight, Venus Express entered the planet's orbit on April 11 with the goal of reaching a elliptical orbit's maximum height of 217,479 miles (350,000 kilometers) below the south pole before swinging back up to pass the minimum height at an altitude of 155 miles (250 kilometers) over the planet's north pole.

The ESA launched its $226 million probe in November 2005. This is the first time since NASA's successful Magellan mission, which ended with the spacecraft's plunge into the Venusian atmosphere in 1994, that the planet has had an orbiter around it.

The most comprehensive study ever conducted of minerals on Mars' surface reveals the planet has undergone three distinct geological eras throughout its history, with water playing a progressively lesser role in each.
If life as we know it here on Earth ever existed on the red planet, it could only have survived in the planet's infancy, during the earliest era, the study concludes.
"Starting about 3.5 billion years ago, conditions on Mars became increasingly dry and acidic—not a pleasant place for any form of life, even a microbe," said study team member John Mustard, a geologist from Brown University.
The mineral maps were created using data from OMEGA, the major spectrometer aboard the Mars Express, as well as related observations collected by other Mars orbiters and the two rovers.
The study, led by Jean-Pierre Bibring from the University of Paris, is detailed in the March 21 issue of the journal Science.
The three faces of Mars
Based on their analyses, the team divided Mars' geological history into three distinct eras:

The first era, which lasted from about 4.6 billion years ago to 4 billion years ago, was a relatively wet one. The oldest rock—exposed by erosion, impact or faulting—showed the presence of clay minerals, such as chamosite and nontronite, that require abundant water, moderate temperatures and low acidity to form.

The next era was drastically different. Massive volcanic eruptions spewed sulfur into the atmosphere, turning the planet's moist and alkaline environment to a dry, acidic one. This period lasted form about 4 and 3.5 billion years and is evidenced by minerals such as gypsum and grey hematite, which were found in Meridiani and in Valles Marineris.

Minerals from the most recent era, which began about 3.5 billion years ago and continues to the present, show no evidence of forming with, or being altered by, liquid water. These iron-rich minerals, mostly ferric oxides, were found across most of the planet and reflect the cold, dry conditions that persist on Mars to this day.

The new study also revealed what is responsible for Mar's reddish hue: most likely, the researchers say, the red planet gets its color from tiny grains of red hematite or possibly maghemite, two minerals that are riddled with iron.

A target for future mission

If Martian life ever did exist, it could probably have only survived during the first era, the team reports. And evidence for that life is most likely to be found in the Syrtis Major volcanic plateau, in Nili Fossae and in the Marwth Vallis Regions, two regions rich in the clay minerals abundant during Mars' youth. The researchers added that these areas would make compelling targets for future lander missions.

By Leonard David
Senior Space Writer
posted: 02 May 2006
12:33 am ET

BOULDER, Colorado – Californians have long been bracing for the "big one" in terms of an earthquake. But the Sun lobs flares that are the most violent events in the solar system. A large flare releases a million times more energy than the largest earthquake.

The relative void between Sun and Earth is loaded with electrically-charged particles, radiation, magnetic field, and electromagnetic energy. The effects from this space weather can range from damage to satellites to disruption of power grids on Earth.

Space weather can wreak havoc on a planet-wide basis. And a look back more than 145 years ago may offer clues as to how harmful a space superstorm might be given our dependence on technological systems.

Understanding and dealing with such consequences was a key issue for nearly 350 industry, academic and government experts taking part in Space Weather Week, held here April 25-28.

Space Weather Week was co-sponsored by the National Oceanic and Atmospheric Administration's (NOAA) Space Environment Center, NASA's Heliophysics Division and the National Science Foundation's Division of Atmospheric Science.

Satellite-linked society

The implications stemming from a geomagnetic superstorm akin to the one that occurred in 1859 would be economically devastating given our reliance upon satellites. That's the view of Sten Odenwald of the QSS Corporation based at the Goddard Space Flight Center in Greenbelt, Maryland.

Odenwald's satellite economic modeling work was melded with historical aspects of the 1859 storm, researched by NASA Goddard scientist, Jim Green. That 1859 event extended over a period from Aug. 28 through to Sept. 3. One impact back then: A significant portion of the world's 140,000 miles of telegraph lines were unusable for a number of hours.

Now, jump to today's satellite-linked society.

Taking a statistical approach is probably the only way to get a global handle on the economic impact, Odenwald told SPACE.com. "Our satellites have collectively shown themselves to be incredibly robust against major failures. Typically during the last solar activity cycle— Cycle 23— only a few satellites seemed to suffer debilitating damage to their ability to operate profitably," he said.

However, Odenwald advised, Earth did not experienced the kinds of space weather conditions expected for a major "superstorm" like the one in 1859.

Statistical confidence level

Hypothetically thinking, Odenwald said, what about a worse-case scenario of an 1859-type superstorm taking place in 2012 at the peak of the next sunspot cycle?

Of the nearly 300 geosynchronous orbiting satellites (GEO) in operation, "such a storm may only actually kill a few dozen of the oldest systems, but will likely reduce the operating life of all the other satellites by 5-10 years," Odenwald said. "That would, in the long run, be a bigger economic catastrophe."

Odenwald projects billions of dollars of lost GEO satellite profit during an 1859-caliber superstorm. The model he has used to reach ballpark numbers includes a realistic treatment of how leased transponders are actually shifted to neighboring satellites from failing "host" satellites.

The estimated profit loss tallies about $30 billion, Odenwald said. That figure is expected to climb higher as he mixes in various types of catastrophic satellite anomalies.

Future work will include collateral economic impacts, pushing the profit loss upwards of $70 billion and higher, Odenwald suggested. "The GEO satellites themselves generate about $97 billion in revenue each year. A superstorm may well eat up most of that revenue for at least a few years."

Odenwald said that his research approach, coupled with more knowledge about how satellites are affected by severe solar storms— some of which is proprietary or classified—will help boost his statistical confidence level.

Dollar impact

A superstorm would influence operations below GEO, among lower-altitude satellites there, too. For one, such a powerful outburst would disrupt civil and government navigation systems like the Global Positioning System (GPS). GPS satellite signals travel through a part of the Earth's atmosphere called the ionosphere to receivers on or near Earth.

GPS is a worldwide radio-navigation system formed from a constellation of satellites and their ground stations. GPS uses the satellites as reference points to calculate positions on the ground accurate to a matter of meters. Space weather disturbances in the ionosphere seriously degrade GPS accuracy.

In his work, Odenwald suggests that roughly a 100 low Earth-orbiting spacecraft would experience an earlier-than-normal reentry. The storm would heat the Earth's upper atmosphere, causing it to expand and therefore increase the drag on satellites.

"The $100 billion International Space Station may lose significant altitude, placing it in critical need for re-boosting by an amount potentially outside the range of typical space shuttle operations, which are in any case scheduled to end in 2010," Odenwald and Green reported.

"So far as I know, my study is the first of its kind, and it leads to some very interesting limits to the dollar impact of severe storms on our satellite industry," Odenwald said.

Earth-Hitting Asteroids: Katrina From Space
By Leonard David

National Space Society
posted: 06 May 2006
11:22 am ET

LOS ANGELES, California – Natural events such as hurricanes, tsunamis and earthquakes rock this planet from time to time. But when the Earth gets stoned by an asteroid, consider it akin to a Katrina from outer space.

When Hurricane Katrina slammed into the United States in August of last year, it became a deadly, destructive, and costly episode—one that has also become a metaphor for lack of government action, both pre- and post strike.

At the current time there is no agency of the U.S. government—nor of any government in the world—with the explicit responsibility to develop and demonstrate the technology necessary to protect the planet from near-Earth object (NEO) impacts.

The U.S. Congress needs to be encouraged to take a step in demonstrating the ability to deflect a menacing NEOs believes former NASA astronaut, Russell Schweickart, Chairman of the B612 Foundation. He presented an update today on dealing with troublesome asteroids here at the 25th International Space Development Conference.

Key capabilities

The goal of B612, a confab of scientists, technologists, astronomers, astronauts, and other specialists is to significantly alter the orbit of an asteroid in a controlled manner by 2015.

In detailing today’s NEO situation, Schweickart said there are several givens: That the Earth is infrequently hit by asteroids which cross our orbit while circling the Sun; the consequence of such impacts ranges from the equivalent of a 15 megaton (TNT) explosion to a civilization ending gigaton event; and for the first time in the history of humankind we have the technology which, if we are properly prepared, we can use to prevent such occurrences from happening in the future.

"Remember, we’re dealing here with a less frequent, but far more devastating Katrina … a Katrina of the Cosmos," Schweickart reported. "NEOs happen so infrequently that even though they are orders of magnitude more devastating, people don’t naturally make that match," he told SPACE.com, "but you don’t want to be caught with your pants down."

There are key capabilities, Schweickart said, which will enable humanity to avoid devastating cosmic collisions: Early warning; a demonstrated deflection capability; and an established international decision making process.

While some progress is being made, there remains significant work ahead in all these areas, Schweickart emphasized.

Sky-sweeping surveys

Given sky-sweeping surveys and extrapolating into the future, by 2018 on the order of 10,000 NEOs with some risk of impact over the next 100 years are likely to be cataloged, Schweickart forecast - but there is better than an even chance that none of these 10,000 will actually hit the Earth in those 100 years.

"The important fact however, is that a substantial number of them will appear as though they may be headed for impact," Schweickart advised. Today, of the 104 currently on impact listings, "two have an elevated risk and we are watching them closely," he said.

At present, the two asteroids on that "keep an eye on them roster" are 2004 VD17 and Apophis, formerly listed as 2004 MN4.

"Extrapolating to 2018 we may have as many as 200 in a similarly elevated attention category and of growing concern to the general public," Schweickart reported today. "Therefore, it is certainly possible, if not likely, that in the timeframe of the next 12 years we—the world—may well be in a position where we need to take action to insure that we will be able to carry out a deflection mission if needed," he said.

The U.S. Congress amended the Space Act in 2005 to charge NASA with responsibility to "detect, track, catalogue, and characterize" NEOs greater than some 460 feet (140 meters) in diameter. However, it has, thus far, come up short on actually assigning the responsibility to take action should one of these objects be discovered headed for a collision, Schweickart pointed out.

There is a bit of good news forthcoming, Schweickart explained. The Congress did require NASA to provide by the end of 2006 an analysis of possible alternatives that could be employed to divert an object on a likely collision course with Earth. In response to this Congressional directive, NASA is about to announce a process for carrying out this mandate.

Global threat … global response

Schweickart told the ISDC audience here, that a third leg of the triad for protecting the Earth from NEO impacts is probably the most challenging, albeit subtle.

"It is complicated by two related facts," he said, that NEO impacts are a global threat, not a national one, and the only decision making body representing, essentially, the whole planet is the United Nations—a body not known for timely, crisp decision making, he added.

Still, in this area, steps forward are being made.

The Association of Space Explorers (ASE)—the professional organization of astronauts and cosmonauts—has formed a committee on NEOs which Schweickart chairs. Earlier this year, a technical presentation at a UN meeting in Vienna apprised them that this issue was coming at them.

While the UN has been brought the problem, Schweickart said, the ASE is committed to bringing them a solution. This solution will take the form of a draft United Nations treaty—or protocol—formulated in a series of workshops over the next two years.

"In these NEO Deflection Policy workshops we will gather together a dozen or so international experts in diplomacy, international law, insurance, and risk management, as well as space expertise to identify and wrestle with these difficult international issues," Schweickart noted. "Our goal is to return to the UN in 2009 with a draft NEO Deflection Decision Protocol and present it to them for their consideration and deliberation."

Facing the challenge

In wrapping up his ISDC talk, Schweickart said the NEO challenge, in a sense, "is an entry test for humankind to join the cosmic community." He reasons that, if there is intelligent life elsewhere in the universe "it is virtually certain that it has already faced this challenge to survival … and passed it."

"Our choice is to face this infrequent but substantial cosmic test … or pass into history, not as an incapable species like the dinosaurs, but as a fractious and self serving creature with inadequate vision and commitment to continue its evolutionary development," Schweickart concluded.

Voyager 2 could pass beyond the outermost layer of our solar system, called the "termination shock," sometime within the next year, NASA scientists announced at a media teleconference today.

The milestone, which comes about a year after Voyager 1's crossing, comes earlier than expected and suggests to scientists that the edge of the shock is about one billion miles closer to the Sun in the southern region of the solar system than in the north.

This implies that the heliosphere, a spherical bubble of charged low-energy particles created by our Sun's solar wind, is irregularly shaped, bulging in the northern hemisphere and pressed inward in the south.

Scientists determined that Voyager 1 was approaching the termination shock when it began detecting charged particles that were being pushed back toward the Sun by charged particles coming from outside our solar system. This occurred when Voyager 1 was about 85 AU from the Sun.

One AU is the distance between the Earth and the Sun, or 93 million miles.

In contrast, Voyager 2 began detecting returning particles while only 76 AU from the Sun.

"This tells us that the shock down where Voyager 2 is must be closer the sun than where Voyager 1 is," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.

The researchers think that the heliosphere's asymmetry might be due to a weak interstellar magnetic field pressing inward on the southern hemisphere.

"The [magnetic] field is only 1/100,000 of the field on the Earth's surface, but it's over such a large area and pushing on such a faint gas that it can actually push the shock about a billion miles in," Stone explained.

Both Voyager spacecrafts were launched from Cape Canaveral Air Force Station in Florida: Voyager 2 headed out on Aug. 20, 1977, Voyager 1 on Sept. 5, 1977.

Currently, Voyager 1 is about 8.7 billion miles from the Sun and traveling at a speed of 3.6 AU per year while Voyager 2 is about 6.5 billion miles away and moving at about 3.3 AU per year.

CALGARY, ALBERTA—A ghostly blue blob amid a swarm of red dots in a new cosmic image is the superhot intergalactic gas permeating the space within the most distant cluster of galaxies found to date.

Located nearly 10 billion light-years away, Cluster XMMXCS 2215-1738 is being hailed by its discoverers as a tantalizing glimpse of what galaxy clusters were like at their earliest stages of formation.

Individual galaxies have been detected at greater distances. But the newly discovered cluster contains several hundred galaxies bound together by mutual gravitational attraction.

The finding was announced here this week at the 208th meeting of the American Astronomical Society.

Young and old

A light-year is the distance that light can travel in a year, so the light from this cluster took almost 10 billion years to reach us. Since the universe is thought to be 13.7 billion years old, the record-setting cluster must have formed when the universe was relatively young.

"Yet this distant cluster appears to be full of old galaxies," discovery team member Adam Stanford noted with amazement.

Stanford and his colleagues said the total mass of the cluster is enough to contain 500 trillion stars comparable in mass to our Sun. That's a surprising stellar mass for a galaxy cluster to have achieved at such an early era in the evolution of the universe, said Stanford, a researcher at the University of California, Davis, and at Lawrence Livermore National Laboratory....

This color image shows the faint red galaxies of the galaxy cluster XMMXCS 2215-1738 in the center, along with the bluish haze which represents the invisible X-ray emission from the extremely hot gas that exists in between the cluster galaxies. Credit: European Southern Observatory Imaging Survey; NOAO

rest of story below:

An asteroid possibly as large as a half-mile or more in diameter is rapidly approaching the Earth. There is no need for concern, for no collision is in the offing, but the space rock will make an exceptionally close approach to our planet early on Monday, July 3, passing just beyond the Moon’s average distance from Earth.

Astronomers will attempt to get a more accurate assessment of the asteroid’s size by "pinging" it with radar.

View from Above: Asteroid 2004 XP14 as seen on June 17 as its path approaches the orbit of Earth. The asteroid will be closest to Earth at 12:25 a.m. EDT July 3. Credit: NASA/JPL

And skywatchers with good telescopes and some experience just might be able to get a glimpse of this cosmic rock as it streaks rapidly past our planet in the wee hours Monday. The closest approach occurs late Sunday for U.S. West Coast skywatchers.

The asteroid, designated 2004 XP14, was discovered on Dec. 10, 2004 by the Lincoln Laboratory Near Earth Asteroid Research (LINEAR), a continuing camera survey to keep watch for asteroids that may pass uncomfortably close to Earth.

Although initially there were concerns that this asteroid might possibly impact Earth later this century and thus merit special monitoring, further analysis of its orbit has since ruled out any such collision, at least in the foreseeable future.

Size not known

Asteroid 2004 XP14 is a member of a class of asteroids known as Apollo, which have Earth-crossing orbits. The name comes from 1862 Apollo, the first asteroid of this group to be discovered. There are now 1,989 known Apollos.

The size of 2004 XP 14 is not precisely known. But based on its brightness, the diameter is believed to be somewhere in the range of 1,345 to 3,018-feet (410 to 920 meters). That's between a quarter mile and just over a half-mile wide.

Due to the proximity of its orbit to Earth [Map] and its estimated size, this object has been classified as a "Potentially Hazardous Asteroid" (PNA) by the Minor Planet Center in Cambridge, Massachusetts. There are currently 783 PNAs.

The latest calculations show that 2004 XP14 will pass closest to Earth at 04:25 UT on July 3 (12:25 a.m. EDT or 9:25 p.m. PDT on July 2). The asteroid’s distance from Earth at that moment will be 268,624-miles (432,308 km), or just 1.1 times the Moon’s average distance from Earth.

Spotting 2004 XP14 will be a challenge, best accomplished by seasoned observers with moderate-sized telescopes.

On April 13, 2029, observers in Asia and North Africa will have a chance to see another asteroid, but without needing a telescope. Asteroid 99942 Apophis, about 1,000 feet (300 meters) wide, is expected to be visible to the naked eye as it passes within 20,000 miles (32,000 km). Astronomers say an asteroid that large comes that close about once every 1,500 years.

Observing plans

As 2004 XP14 makes its closest approach to Earth, astronomers will attempt to gauge its size and shape by analysis of very high frequency radio waves reflected from its surface.

Such radar measurements of the exact distance and velocity of the asteroid will allow for precise information on its orbit. From this scientists can also discern details of the asteroid’s mass, as well as a measurement of its density, which is a very important indicator of its overall composition and internal structure.

Astronomers plan to utilize NASA's 70-meter (230-foot) diameter Goldstone radar, the largest and most sensitive antenna in its Deep Space Network. Located in California’s Mojave Desert, the Goldstone antenna has been used to bounce radio signals off other Near-Earth asteroids many times before, and it is now being readied to "ping" 2004 XP14 on July 3, 4 and 5.

Augmenting the Goldstone observations will be radar observations scheduled at Evpatoria in the Ukraine, commencing several hours prior to the July 3 observations at Goldstone.

Discovery Hints at a Quadrillion Space Rocks Beyond Neptune

By Sara Goudarzi
Staff Writer
posted: 15 August 2006
06:13 am ET

Dozens of rocky bodies that are part of a sea of small rocky fragments never observed before have been spotted in the suburbs of our solar system beyond planet Neptune, thanks to a novel technique.

These newly detected chunks of dust and rock coined Trans-Neptunian Objects (TNO) are smaller than 330 feet (100 meters) across. They are leftovers from the formation of planets.

Scientists had previously detected TNOs larger than 31 miles (50 kilometer) across such as the Kuiper Belt Objects (KBO), a subset of TNOs. They suspected that there may be distant objects beyond Neptune since the 1940's, but it wasn't until 1992 that the first KBO was discovered.

Since then, they've found so many large objects in the outskirts of the solar system that they had to come up with crazy names, like Plutinos, Centaurs, and Cubewanos, to keep them in order. And although researchers suspected the presence of smaller objects, they didn't have a way to detect the sea of debris.

"The searches for Kuiper Belt Objects usually look for reflected light from the Sun and the small motion relative to fixed background stars," said Asantha Cooray, assistant professor of Physics and Astronomy at the University of California, Irvine. The amount of reflected light from a small body, however, is so extremely dim that not even the largest telescopes, or much larger telescopes one could imagine building either on Earth or space, could see it.

But scientists didn't look for the reflected light this time. Examining data from NASA's Rossi X-ray Timing Explorer, they monitored the light from a background star, Scorpius X-1, as small objects moved in front of it in what are called occultations. They found obvious dips in the light.

Other than the Sun, Scorpius X-1 is the brightest X-ray source in the sky, said study leader Hsiang-Kuang Chang, Associate Professor of Physics & Institute of Astronomy at the National Tsing Hua University, Taiwan.

"We discussed various possibilities for causing these dips and concluded that occultation by small TNOs are the most likely one," he told SPACE.com in an email interview.

Alltogether, Chang and colleagues identified 58 definite dips. Their findings are detailed in the Aug. 10 issue of the journal Nature.

Observing occultations is a widely known method for studying foreground objects by monitoring the light of background stars. The rings of Uranus were first discovered during an occultation of a star by Uranus. But never have such small objects been detected this way.

"The interesting thing here is that instead of monitoring optical stars, these authors monitor light from an X-ray source since X-ray detectors can record light at small time intervals compared to optical detectors," Cooray told SPACE.com. "A 100-meter body only occults a background source for about 10 milliseconds and optical detectors cannot record light continuously at such small time intervals."

Based on this finding, the researchers estimate that the number of TNOs reaches around a quadrillion, rather than the mere billions to a trillion as previously thought.

This shows an extremely dense disk of material at the outer edges of the solar system mostly populated by smaller bodies, Cooray said. "Since these are leftover material from the solar system formation process, it says that the original disk from which the planets formed was more massive at distances around Neptune than previously suggested and in strong conflict with some of the early models for the formation of Kuiper Belt Objects."