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PRAGUE, Czech Republic — Leading astronomers declared Thursday that Pluto is no longer a planet under historic new guidelines that downsize the solar system from nine planets to eight.
After a tumultuous week of clashing over the essence of the cosmos, the International Astronomical Union stripped Pluto of the planetary status it has held since its discovery in 1930.
The new definition of what is — and isn’t — a planet fills a centuries-old black hole for scientists who have labored since Copernicus without one.
Although astronomers applauded after the vote, Jocelyn Bell Burnell — a specialist in neutron stars from Northern Ireland who oversaw the proceedings — urged those who might be “quite disappointed” to look on the bright side.
“It could be argued that we are creating an umbrella called ‘planet’ under which the dwarf planets exist,” she said, drawing laughter by waving a stuffed Pluto of Walt Disney fame beneath a real umbrella.
The decision by the prestigious international group spells out the basic tests that celestial objects will have to meet before they can be considered for admission to the elite cosmic club.
For now, membership will be restricted to the eight “classical” planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Much-maligned Pluto doesn’t make the grade under the new rules for a planet: “a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit.”
Pluto is automatically disqualified because its oblong orbit overlaps with Neptune’s.
Instead, it will be reclassified in a new category of “dwarf planets,” similar to what long have been termed “minor planets.”
The definition also lays out a third class of lesser objects that orbit the sun — “small solar system bodies,” a term that will apply to numerous asteroids, comets and other natural satellites.
It was unclear how Pluto’s demotion might affect the mission of NASA’s New Horizons spacecraft, which earlier this year began a 9˝-year journey to the oddball object to unearth more of its secrets.
The decision at a conference of 2,500 astronomers from 75 countries was a dramatic shift from just a week ago, when the group’s leaders floated a proposal that would have reaffirmed Pluto’s planetary status and made planets of its largest moon and two other objects.
That plan proved highly unpopular, splitting astronomers into factions and triggering days of sometimes combative debate that led to Pluto’s undoing.
Now, two of the objects that at one point were cruising toward possible full-fledged planethood will join Pluto as dwarfs: the asteroid Ceres, which was a planet in the early 19th century before it also got demoted, and 2003 UB313, an icy object slightly larger than Pluto whose discoverer, Michael Brown of the California Institute of Technology, has nicknamed “Xena.”
Charon, the largest of Pluto’s three moons, is no longer under consideration for any special designation.
Brown was pleased by the decision. He had argued that Pluto and similar bodies didn’t deserve planet status, saying that would “take the magic out of the solar system.”
“UB313 is the largest dwarf planet. That’s kind of cool,” he said.
SAN FRANCISCO — A NASA physicist said Friday he had found what may be the fossilized remains of extraterrestrial microorganisms in a meteorite, providing more evidence that life may have existed beyond Earth.
Astrophysicist Richard Hoover said that while investigating samples of the Murchison meteorite that fell on Australia in 1969, he had found complex structures that appeared to be biological.
“It is potentially the case that it’s signs of life from somewhere other than the planet Earth. That is a real possibility that must be considered,” Hoover told Reuters in a telephone interview from San Diego.
Hoover, an astrophysicist at the National Aeronautics and Space Administration’s George C. Marshall Space Flight Center in Huntsville, Alabama, cautioned that more study was needed and he could not say for sure where the microscopic structures came from.
Hoover’s work appears to support the findings of U.S. scientists who announced last year that they had found possible fossilized microbes in a meteorite from Mars.
In a scientific paper presented at a conference in San Diego this week, Hoover said he had concluded that the Murchison meteorite contained “a population of indigenous microfossils,” shaped like mushrooms, stalks or filaments.
The mushroom-shaped bodies “are considered to represent the carbonized remains of biological forms,” he wrote.
Hoover obtained images of the forms using an environmental scanning electron microscope and analyzed them with x-ray energy dispersive spectroscopy.
The bodies resembled some types of bacteria, but experts had been unable to identify them as known earthly microbial groups, Hoover said. He said the bodies resembled other unidentifiable forms found in another meteorite by earlier researchers.
“It is concluded that this population of complex structures may represent remains of extraterrestrial microorganisms which lived within or contaminated the parent body of the Murchison meteorite at various times during the past 4.4 billion years,” Hoover wrote.
The parent body of the Murchison meteorite is unknown, but Hoover said there was strong evidence that it did not come from Earth, the moon or Mars and may have come from a comet or asteroid.
He said the structures he had observed appeared to have arrived on Earth with the meteorite and not be something that found its way there after it landed.
It was also possible that asteroid impacts on Earth billions of years ago could have catapulted materials from Earth into space and that any microfossils in the meteorite could have originated on Earth. But the same thing could have happened on Mars or another body, he said.
“We are doing additional work to determine what (the structures) are ... and to determine if we can obtain carbon isotope measurements to give an idea of whether they are terrestrial or extraterrestrial in nature.”
He said that earlier this year a scientific team in Russia reported finding similar structures within the Murchison meteorite.
Hoover said scientists must continue studying meteorites.
“The meteorites are messages from space. They are bringing us information that we must study and learn, telling us where to go to seek conclusive proof for the existence of extraterrestrial life,” he said.
NEW YORK — Imagine you were small and green and wanted to contact life on planet Earth more than 100 light years away. How would you do it?
It may not be something most think about every day, but Robin Corbet, a Universities Space Research Association astrophysicist working at NASA’s Goddard Space Flight Center, recently placed himself in the little green shoes of a supposed distant alien. He suggests that, in the search for extraterrestrial signals, timing is everything.
“If there really are aliens out there trying to contact us,” Corbet said, “they would want to synchronize the message with some large event. And gamma ray bursts are the most natural thing to use because it’s such a dramatic event.”
Scientists have long proposed that aliens trying to contact Earth would time their messages around large astronomical phenomena. By sending a signal on the tail of a brilliant celestial explosion, aliens could ensure that many eyes would be trained in the direction of their message. Once people spotted the celestial event, it would be followed by a message from the far away planet.
Russian scientists first suggested aliens might send their signals on the tail of a supernova in the 1970s. But in a paper that will soon appear in Publications of the Astronomical Society of the Pacific, Corbet claims that a gamma ray burst, not a supernova, would be the best place to look for signs of alien life.
“If aliens are trying to decide on something happening in the sky to synchronize communications, it would make sense to use the most powerful type of explosion out there,” said Corbet, who works with funding from the USRA.
As far as scientists know, gamma ray bursts are the most powerful and dazzling events in space. The mysterious blasts of electromagnetic radiation often appear brighter than all the stars in the universe combined. Scientists are still unsure if the blasts are caused by two neutron stars colliding, or, perhaps, by a neutron star falling into a black hole, but satellites have been detecting at least one of the bursts every day since 1991.
Recently satellites have gathered readings accurate enough to point ground-based telescopes toward the bursts. In fact, last January, astronomers were able to view the live explosion of the largest gamma ray burst ever recorded when orbiting detectors saw the burst within seconds and signaled computers to point ground-based telescopes in the direction of the blast.
As new, specially engineered satellites are launched into space in the next few years, scientists predict they will be able to precisely locate up to 300 gamma ray bursts a year. In contrast, only four supernovae have been positively identified in recorded history.
“This idea has the wonderful advantage that you don’t have to sit around and wait for years for the event to happen,” said Seth Shostak, an astronomer at the Search for Extraterrestrial Intelligence Institute (SETI). “They’re more frequent and better defined in time.”
The frequency of the gamma ray bursts would also allow aliens to wait for the perfect opportunity to send their message when both Earth and their planet were aligned with the burst. Such an alignment would ensure that Earthlings get a direct view of both the burst and the alien signal. The extremely remote locations of gamma ray bursts also means that we may witness the blasts at about the same time as anything living on distant planets.
Finally, because gamma ray bursts are usually over in a matter of seconds, Corbet points out that aliens would only need to send out a quick, very concentrated message to piggyback onto the event.
“If these are frugal aliens who don’t want to spend too much energy to transmit energy out, then they would need a brief event — like a gamma ray burst — to make their transmission more efficient,” he said.
While searching around the edges of gamma ray bursts for alien messages may be logical in theory, it is an idea that, by necessity, makes huge assumptions. The first, of course, is that there is other intelligent life in the universe. But, furthermore, Carl Akerlof, a physicist at the University of Michigan, points out that human logic may not necessarily mesh with that of other life forms.
“By guessing how aliens might contact us, we are assuming that we’re on the same intellectual plane,” Akerlof said. “But you can imagine it would not be very fruitful to send a TV broadcast to a very primitive tribe, or the other way around.”
Radio communication, Akerlof points out, has only existed on Earth for about 100 years. If there is other intelligent life elsewhere, many assume their technology may be much more advanced than our own. That means aliens could be signaling us right now and we simply do not have the ability to detect it.
The main problem with Corbet’s idea, however, is astronomers at SETI say they are not yet equipped to follow-up. According to Shostak, neither of the two facilities where SETI is licensed to work, have the ability to zero-in on a location quickly.
“Unless a gamma ray burst happens to occur straight above our scope in Puerto Rico, for example, we would have to wait for the Earth to turn,” Shostak said. “That could take up to 12 hours and by then, the event may no longer be interesting.”
Corbet points out that if there is a less than perfect alignment between the aliens, the burst and Earth, astronomers may actually have more time to focus on the burst and catch an alien message. He calculates that a one degree difference in alignment could amount to a nine day delay between the burst and an alien message. The problem then becomes knowing how long to wait for a message after a burst. To know that, astronomers would need to learn the approximate location of the aliens. And locating aliens, of course, remains the main problem.
Nonetheless, Shostak said if SETI could get the money and the means, he would be “all for the idea” of searching for signals around gamma ray bursts and other celestial events. Since more than 35 years of listening in on distant stars has failed to turn up anything lifelike, Shostak and others at SETI are eager to explore new strategies.
“So far,” Shostak said, “the aliens remain coy.”
NEW YORK (AP) — Astronomers have found an icy miniplanet that orbits the sun well beyond Pluto, providing evidence that the solar system extends much farther than was once thought.
The little planet is about 300 miles across, which gives it a surface area comparable to Texas. It is the brightest solar system object to be found beyond Neptune since the discovery of Pluto’s moon Charon in 1978.
At its most distant, it wanders three times farther from the sun than Pluto, tracing a looping, oblong path into an astronomical terra incognita.
“It’s the first object in a sort of no man’s land, an area we never thought we could get a glimpse of with our current technology,” said Jane Luu, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
And it’s probably not alone. Theoretical calculations suggest that there are millions of small, icy solar system objects well beyond the outermost planets.
Astronomers consider their new discovery an extension of the Kuiper belt, a collection of small, icy bodies that circle the sun beyond the orbit of Neptune. About 40 Kuiper belt objects have been discovered since 1992.
Before then, the only known Kuiper belt objects were the planet Pluto, discovered in 1930, and Charon.
Luu discovered the new object, known as 1996TL66, with colleagues from Harvard, the University of Hawaii and the University of Arizona, as well as an amateur astronomer based in Cloudcroft, N.M. They describe the find in Thursday’s issue of the journal Nature.
“I wouldn’t call this a major planet,” said Brian Marsden, a Harvard astronomer and contributer to the Nature paper. “But then I tend not to call Pluto a major planet.”
In fact, 1996TL66 is considered too minor to be named for a Roman god, like the other planets.
Astronomers surmise that it is composed of the same material as other outer solar system objects — water, carbon dioxide, methane and other materials — all frozen solid.
The astronomers found 1996TL66 with a University of Hawaii telescope as the object passed among the outer planets last October. They and others followed it for several months with telescopes in Hawaii, Arizona and New Mexico.
The object’s motion over the last few months shows that it follows a lopsided orbit unlike that of any other Kuiper belt object. It swings through the neighborhood of the outermost planets every 800 years, then loops far out into space before making its next pass.
Astronomers have never seen such a thing.
“It just reminds us that we really don’t know what the outer solar system holds,” Luu said.
Some researchers had an inkling that the object would be out there, however. Hal Levison, a scientist at the Southwest Research Institute in Boulder, Colo., has been telling his colleagues for the past year that objects such as 1996TL66 ought to exist.
The research behind that prediction, conducted with Martin Duncan of Queen’s University in Canada, is scheduled for publication in a future issue of the journal Science.
“Though we knew that we had an interesting scientific result, it just never occurred to me that anybody would find one,” Levison said. “It’s very satisfying when someone confirms your theories.”
In his Science paper, Levison describes how Uranus and Neptune probably generated the Kuiper Belt during the formation of the solar system more than 4 billion years ago. According to that theory, Neptune kicked a small percentage of the Kuiper belt objects into oblong orbits such as the one followed by 1996TL66.
Luu and her colleagues found the object at the very beginning of a systematic search for objects at the edge of the solar system. Because it was so easy to find, the researchers calculate that there are hundreds, and perhaps more than 1,000, objects similar to 1996TL66.
“Unless we are improbably lucky, it is merely the first detected of a larger population of similar bodies,” the astronomers wrote.
PHILADELPHIA — A surprisingly sturdy little galaxy is barging right into the Earth’s own Milky Way but it will probably be sucked in rather than cause any damage, astronomers said Friday.
And no one on Earth needs to worry — it probably won’t happen for another three to five billion years, and in any case would have little effect on this planet.
The little galaxy, known as the Sagittarius dwarf spheroidal galaxy, could help astronomers figure out the secret of “dark matter”, which measurements show must make up about 90% of the universe but which has yet to be seen.
“Is there dark matter in this galaxy?” Rosemary Wyse, an astrophysicist at Johns Hopkins University in Baltimore, asked at a news conference at the American Association for the Advancement of Science annual meeting in Philadelphia.
“Is it the same as dark matter we believe existed in larger galaxies?”
Wyse worked with a team of astronomers including Rodrigo Ibata from the European Southern Observatory in Chile, and Mike Irwin at the Royal Greenwich Observatory and Gerard Gilmore of the Institute of Astronomy in Britain. These three originally saw the Sagittarius dwarf galaxy in 1994.
They and Wyse have made new observations that show the galaxy must orbit our Milky Way every billion years. Gravity from the much larger and massive Milky Way should have started pulling it apart, but it hasn’t.
Wyse says this must come down to dark matter — matter that cannot be seen by conventional means but which makes its presence known by it effects on gravity, and on galaxies like the Sagittarius dwarf.
“It’s just got a lot of dark matter, so it’s able to hold on to its stars,” Wyse said.
Having this dwarf galaxy nearby might let astronomers have a close-up peek at what dark matter looks like.
Dark matter is key to the future of the universe. How much matter there is will determine if the Big Bang that started it all will end in a Big Crunch, or a never-ending expansion.
Wyse said dark matter might include dim stars, but there had to be more to it than that. “One of the interesting things is that there might be more than one kind of dark matter,” she said.
Right now it can be seen only by its gravitational effects — it pulls on light from far-away galaxies, an effect called gravitational lensing.
Most galaxies, including the Sagittarius dwarf, seem to have a big halo of dark matter that attracts them to one another as they pass by on their cosmic journeys. There is so much it creates a kind of wake as they come together, said Chris Mihos of Case Western Reserve University in Ohio.
Having Sagittarius merging so close by also gives astronomers a chance to see what might happen on a bigger scale, when the Milky Way’s next-door neighbor, the Andromeda galaxy, comes crashing in.
The Andromeda galaxy is two million light years away, a light year being the distance light travels in a year at 186,000 miles per second, so it will not hit the Milky Way for billions of years.
Mihos said there was no worry to any Earthlings that might have survived that long.
“If you shrunk the Sun down to the size of a marble, the next star would be somewhere out in the Caribbean,” he said.
“So we don’t have to worry about another star smacking into our star.”
THE Universe began as a tiny particle, Stephen Hawking, the scientist and bestselling author has concluded.
The Lucasian Professor of Mathematics at Cambridge University has turned his attention to what may have been happening in the fraction of a second before Big Bang. Professor Hawking and Neil Turok, also of Cambridge, believe that not only was there a microscopic particle but that it was expanding in a process known as inflation just before Big Bang, a huge explosion about 12 billion years ago whose heat created the atomic particles needed for stars and galaxies to form.
Their theory, based on one put forward by Professor Hawking in 1983 and Einstein’s theory of gravity, also concludes that the Universe will expand for ever.
Some scientists believe that the Universe will eventually collapse in a “big crunch”. But the new theory, called Open Expansion, rejects this and claims that the Universe is infinite. Professor Turok, who holds the chair of mathematical physics, said yesterday: “It sounds rather surprising. How do you start off with a finite object that becomes infinite?”
He said the theory pointed to the Universe being cone-shaped, having started out as a dot in space and time and expanding like an ice-cream cornet over the 12 billion years.
Professor Hawking will outline the theory at a meeting next month at the California Institute of Technology.
SAN FRANCISCO — Astronomers have discovered a planet bigger than Jupiter just 15 light years from Earth, apparently a huge ball of gas with a surface temperature well below zero.
Geoffrey Marcy, who heads a four-member team of San Francisco State researchers, announced the discovery this week at a scientific symposium in Canada. The finding was confirmed by a separate team in Switzerland.
The group found the planet using the Keck I telescope in Hawaii.
Its huge mass — at least 1.9 times bigger than Jupiter’s — was detected by a wobble in the motion of a nearby star, not by direct visualization.
There is no evidence of any solid land on the planet on which earthlike life forms might have developed. Scientists say the planet is mostly hydrogen and helium with a surface temperature of about 80 degrees below zero.
The planet was the first to be found orbiting a small star called Gliese 876, one-third the size of the sun. The star is the closest to Earth — other than our own sun — around which a planet has been found.
It is one of the closest members of a class of low-mass stars that are the most common in the Milky Way galaxy.
The previously closest-known “extrasolar” planet orbits a star about 35 light-years away. A light-year is 5.9 trillion miles, the distance light travels in one year.
“It’s not spitting distance, exactly, but spacecraft distance perhaps for future generations,” Marcy said Wednesday.
Marcy added that the discovery of a planet around Gliese 876 dramatically raises the odds that many more planets may be found relatively close to our own solar system.
“The key issue is that this is by far the lowest-mass star around which a planet has ever been discovered,” he said.
Twelve such planets have been discovered by the world’s astronomers, including seven by Marcy and his associates in the past three years. A report on the most recent discovery will be published in Saturday’s issue of Science News.
PASADENA, Calif. — With one rover now ailing on Mars, NASA scientists were thrilled when its identical twin sent dazzling and intriguing photos from the other side of the Red Planet.
Images of a smooth red surface arrived at NASA’s Jet Propulsion Laboratory about four hours after the rover Opportunity bounced to a landing late Saturday some 6,600 miles from its temporarily crippled twin, Spirit.
“I am flabbergasted. I am astonished. I am blown away. Opportunity has touched down in an alien and bizarre landscape,” said Steven Squyres, of Cornell University and the mission’s main scientist. “I still don’t know what we’re looking at.”
Mission members hooted and hollered as the images splashed on a screen in mission control at the laboratory in Pasadena. Gov. Arnold Schwarzenegger was there with his wife, Maria Shriver, to watch the drama unfold, and walked through mission control shaking hands with the scientists.
“The pictures just blow me away. We’ve certainly not been to this place before,” deputy project manager Richard Cook said.
Opportunity plunged into the martian atmosphere at more than 12,000 mph and bounced down on Mars just six minutes later, swaddled in protective air bags. It hit with a force estimated to be just two to three times that of Earth’s gravity. Engineers had designed it to withstand as much as 40 G’s.
The six-wheeled rover landed in Meridiani Planum, believed to be the smoothest, flattest spot on Mars. Opportunity lies 6,600 miles and halfway around the planet from where its twin, Spirit, landed on Jan. 3.
On Sunday, NASA said Opportunity was in excellent health and Spirit was on the mend after a serious software problems had hobbled it.
Initial analysis of the images suggested Opportunity landed in a shallow crater roughly 66 feet across. Its low rim shouldn’t block the rolling robot once it gets going, Squyres said.
Opportunity could roll off its lander in 10 to 14 days’ time, mission manager Arthur Amador said. Opportunity’s possible targets include a larger crater, maybe 500 feet across, that lies an estimated half-mile from where the spacecraft landed.
The rover’s ramp off its lander also appeared unobstructed, unlike Spirit’s landing, when a deflated air bag blocked its safest route to the martian surface, said Matt Wallace, another of the mission managers.
Together, the twin 384-pound rovers make up a $820 million mission to seek out geologic evidence that Mars was once a wetter world possibly capable of sustaining life. NASA launched Spirit on June 10 and Opportunity on July 7. Each carries nine cameras and six scientific instruments.
On Wednesday, Spirit developed serious problems, cutting off what had been a steady flow of pictures and scientific data.
Engineers now believe the problem arose with software that manages the file system within the rover’s flash memory, project manager Pete Theisinger said. Other possible culprits include broken hardware or solar radiation.
“Spirit is still serious but we are moving to guarded condition,” Theisinger said, adding Spirit could resume normal operations in two to three weeks.
NASA sent Spirit to Gusev Crater, a broad depression believed to once have contained a lake. Opportunity was sent to Meridiani Planum, which scientists believe abounds in a mineral called gray hematite.
The iron-rich mineral typically forms in marine or volcanic environments marked by hydrothermal activity. Hematite is common in the red soil found across the Southeastern United States and is frequently used as a pigment, said Doug Ming, of NASA’s Johnson Space Center and a member of the science team.
NASA launched two rovers to double its chances of successfully landing on Mars. Both carry identical plaques memorializing the seven astronauts who died aboard space shuttle Columbia nearly a year ago, Opportunity mission manager Jim Erickson said.
As of early Sunday, there were a record five spacecraft operating on or around Mars, including two NASA satellites and one from the European Space Agency orbiting the planet.
PASADENA, Calif. — In a discovery that offers a rare glimpse back to when the universe was just 750 million years old, a team of astrophysicists said Sunday they have detected a tiny galaxy that is the farthest known object from Earth.
“We are confident it is the most distant known object,” California Institute of Technology astronomer Richard Ellis said of the galaxy, which lies roughly 13 billion light-years from Earth.
The team uncovered the faint galaxy using two of the most powerful telescopes — one in space, the other in Hawaii — aided by the natural magnification provided by a massive cluster of galaxies. The gravitational tug of the cluster, called Abell 2218, deflects the light of the distant galaxy and magnifies it many times over.
The magnification process, first proposed by Albert Einstein and known as “gravitational lensing,” produces double images of the galaxy.
“Without the magnification of 25 afforded by the foreground cluster, this early object could simply not have been identified or studied in any detail with presently available telescopes,” said astronomer Jean-Paul Kneib, of Caltech and the Observatoire Midi-Pyrenees in France.
The discovery gives a rare glimpse of the time when the first stars and galaxies began to blink on, ending a period that cosmologists call the Dark Ages, said Robert Kirshner, an astronomer with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
“The possibility is here we really are beginning to peek into that time,” said Kirshner, who was not connected with the discovery. “People have gone there in their imagination — they’ve thought about it. Now we are getting the facts.”
The Hubble Space Telescope revealed the first glimpse of the galaxy, backed up by observations made with the Keck Observatory’s 10-meter telescopes atop Mauna Kea.
The galaxy is just 2,000 light-years across. That’s far smaller than the Milky Way, which is roughly 100,000 light-years in diameter.
Cosmologists have predicted that early galaxies contained stars that were different from the ones that came into being much later in the history of the universe. But the astrophysicists’ analysis suggests that the type of massive stars the galaxy contains were common after the end of the Dark Ages, Ellis said.
“That’s very interesting if it’s true,” Kirshner said.
No one knows how long the Dark Ages lasted in the wake of the Big Bang 13.7 billion years ago.
Word of the discovery came during the annual meeting of the American Association for the Advancement of Science in Seattle. Further details appear in a forthcoming issue of the Astrophysical Journal.
Using two orbiting observatories, astronomers are for the first time seeing a black hole destroy a star. As depicted in the illustration above, the hole drags and stretches the star to such an extent that fragments fly off. It happened 700 million years ago in the constellation Virgo and its light is reaching us only now.
LONDON — After almost 30 years of arguing that a black hole swallows up everything that falls into it, astrophysicist Stephen Hawking backpedaled Thursday. In doing so, he lost one of the most famous bets in recent scientific history.
The world-famous author of a “Brief History of Time” said he and other scientists had gotten it wrong — the galactic traps may in fact allow information to escape.
“I’ve been thinking about this problem for the last 30 years, and I think I now have the answer to it,” Hawking told the British Broadcasting Corp.’s “Newsnight” program.
“A black hole only appears to form but later opens up and releases information about what fell inside. So we can be sure of the past and predict the future.”
The findings, which Hawking is due to present at the 17th International Conference on General Relativity and Gravitation in Dublin, Ireland, on July 21, could help solve the “black hole information paradox,” which is a crucial puzzle of modern physics.
Exactly what happens in a black hole — a region in space where matter is compressed to such an extent that not even light can escape from its immense gravitational pull — has long puzzled scientists.
Black holes occur when a massive star burns up its nuclear fuel and gravity forces it to collapse in on itself, and the enormous weight of the star’s outer layers implodes its core. The crushing force of gravity prohibits nearly all light from escaping and nothing inside can be glimpsed from the outside.
The star virtually disappears from the universe into a point of infinite density, a place where the laws of general relativity that govern space and time break down.
Hawking has devoted most of his life to studying these questions.
Initially, cosmologists believed the holes were like a cosmic vacuum cleaner, sucking up everything in their path.
Hawking revolutionized the study of the holes when he demonstrated in 1976 that, under the strange rules of quantum physics, once black holes form they start to “evaporate” away, radiating energy and losing mass in the process.
Under this theory, black holes are not totally “black” because the vacuum of the imploding star lets out very tiny amounts of matter and energy in the form of photons, neutrinos and other subparticles.
By conjuring up this so-called “Hawking radiation,” the Cambridge mathematician, who is paralyzed by amyotrophic lateral sclerosis, also created one of the biggest conundrums in physics.
These particles, he said, contained no information about what has been occurring inside the black hole, or how it formed. Under his theory, once the black hole evaporates, all the information within would be lost.
But now, according to his latest revision, Hawking argues that eventually some of the information about the black hole can be determined from what it emits.
The information has important philosophical and practical consequences.
“We can never be sure of the past or predict the future precisely,” he said. “A lot of people wanted to believe that information escaped from black holes but they didn’t know how it could get out.”
Hawking did not elaborate on the BBC program how the information could be extracted from the black hole.
Curt Cutler, from the Albert Einstein Institute in Golm, Germany, which is chairing the meeting in Dublin, told New Scientist magazine that Hawking asked at the last minute for permission to address the conference.
“He sent a note saying ‘I have solved the black hole information paradox and I want to talk about it,”‘ Cutler said.
If Hawking succeeds in making his case, he will lose a bet that he and theoretical physicist Kip Thorne of the California Institute of Technology made with John Preskill, also of Caltech.
The terms of the bet were that “information swallowed by a black hole is forever hidden and can never be revealed.”
Preskill bet against that theory.
The forfeit is an encyclopedia, from which Preskill can recover information at will.
DUBLIN — Cosmologist Stephen Hawking lost one of the most famous bets in scientific history yesterday after he rejected the 1975 black-hole theory that helped make his name.
The best-selling author of “A Brief History of Time” conceded that American physicist John Preskill was right to doubt the theory and gave him a baseball book as a prize.
“I am now ready to concede the bet,” said Mr. Hawking, 62. “I offered him an encyclopedia of cricket, but John wouldn’t be persuaded of [its] superiority.”
Mr. Hawking, who has a crippling muscle disease and is confined to a wheelchair, accepted the bet in 1997 when Mr. Preskill refused to accept that black holes permanently destroy everything they consume.
For more than 200 years, scientists have puzzled over black holes, which form when stars burn all their fuel and collapse, creating a huge gravitational pull.
Mr. Hawking now thinks some material oozes out of the black holes over billions of years through tiny irregularities in their surface.
He gave brief details of his U-turn last week and expanded on them at a conference in Dublin after making a last-minute request to speak.
“I always hoped that when Stephen conceded, there would be a witness. This really exceeds my expectations,” said Mr. Preskill, pointing at the banks of TV cameras in the packed auditorium.
He said he would miss the years of debate provided by the so-called “black hole information paradox,” over whether material can escape.
Others said they would wait for Mr. Hawking’s new theory to be published before making up their minds.
“This looks to me, on the face of it, to be a lovely argument,” said Kip Thorne, a colleague of Mr. Preskill’s at the California Institute of Technology. “But I haven’t seen all the details.”
Mr. Hawking said his reworked theory ruled out his earlier belief that people someday could use black holes to travel to other universes.
“I am sorry to disappoint science fiction fans,” he said through his distinctive computerized voice box. “But if you jump into a black hole, your mass energy will be returned to our universe but in a mangled form.”
Mr. Hawking, a father of three and Lucasian professor of mathematics at Cambridge University, was diagnosed with motor neuron disease at 21 and told he had only a few years to live.
He defied doctors and went on to sell 10 million copies of his study of the universe, “A Brief History of Time.”
He cemented his popular image with guest appearances on “Star Trek: The Next Generation” and “The Simpsons.”
LOS ANGELES — Astronomers say the mysterious, massive black hole at the center of the Milky Way(search) helped give birth to new stars, challenging earlier theories that black holes are solely destructive forces.
Scientists peering through NASA’s Chandra X-ray Observatory found that disks of gas near the black hole actually helped spawn a new generation of stars.
Their observations, announced Thursday, will be published in a future issue of the Monthly Notices of the Royal Astronomical Society.
“Massive black holes are usually known for violence and destruction,” said Sergei Nayakshin of the University of Leicester in England, who made the discovery. “So it’s remarkable that this black hole helped create new stars, not just destroy them.”
Black holes are believed to be the invisible remains of collapsed stars. Their gravitational pull is so powerful not even light can escape.
This Jekyll-and-Hyde nature suggested by the new discovery may help scientists understand the physics of black holes, said Sterl Phinney, a professor of theoretical astrophysics at the California Institute of Technology in Pasadena, who was not part of the study.
Astronomers believe the gravity of the gas disks helped offset the tidal force of the black hole in a tug-of-war that allowed the stars to form.
Scientists have ruled out the possibility that a star cluster formed far away and somehow migrated near the black hole. Some 10,000 low-mass stars formed near the black hole. If there had been a migration, scientists surmised they would have found at least a million such stars.
The Milky Way is a spiral galaxy, a cluster of stars with a black hole in the center and bending arms spreading out from the core. The solar system, containing the Earth and other planets, is on one of the spiral arms.
NEW YORK — Astronomers say they’ve found what may be the smallest and most distant planet known to be orbiting a star outside our own solar system.
The work suggests that such small rocky or icy planets may be more common in the cosmos than Jupiter-sized gas giant planets, researchers said. The discovery also indicates the power of a relatively new method of finding such “exoplanets.”
All of the exoplanets discovered so far around distant stars are larger than Earth. The newly found planet is about 5.5 times the mass of Earth, making it much smaller than most of the 160 previous exoplanet discoveries.
It appears to be less massive than another small planet found recently, but because of uncertainties in estimating mass that isn’t known for certain, the scientists said.
The finding was reported in the journal Nature by a team of researchers from 12 countries.
Similarly, at a distance of more than 20,000 light years from Earth, it is probably the most distant such planet yet found, said study co-author David Bennett of the University of Notre Dame. But distance estimates are too uncertain to be highly confident of that, he said.
In any case, the planet appears to be much too cold to sustain life, probably reaching no more than minus 364 degrees, the researchers said. It orbits its star about about 2.6 times the distance between Earth and the sun.
The planet lies in the constellation Sagittarius, close to the center of the Milky Way.
Nearly all the known exoplanets have been detected by their gravitational tug on the stars they orbit, which makes the stars wobble. The new planet is the third to be uncovered by a different technique, which uses the fact that a celestial body’s gravity bends light like a cosmic glass lens.
If a planet and its star pass between Earth and a more distant star, this “microlensing” effect gives a temporary but telltale boost to the brightness of the more distant star. This technique opens the door to finding relatively small planets with masses and orbits similar to Earth’s, researchers said.
It has uncovered only two huge Jupiter-size planets so far, and it probably would have found dozens by now if they were as common as smaller planets, Bennett said. So it appears the small planets are much more common than the big ones, he said.
Jean-Philippe Beaulieu of the Astrophysical Institute in Paris, another author of the paper, said he expected that in the future, the international team that found the new planet “will get a handful like this per year.”
The astronomers named the planet OGLE-2005-BLG-390Lb. “OGLE” is the group of astronomers who monitor stars for evidence of microlensing.
LOS ANGELES — It’s official — the so-called “10th planet” discovered last year is bigger than Pluto.
However, that may not mean much, since astronomers can’t agree on exactly what a planet is, or even if Pluto itself qualifies as one.
The discoverers of the “planet,” a Kuiper Belt object semi-officially known as 2003 UB313, gave only a rough estimate of its size, based on its brightness, when they reported their findings in July 2005.
That team — Michael Brown and Chad Trujillo of the California Institute of Technology and David Rabinowitz of Yale University — found the object, and its moon, by analyzing photographs taken by a telescope at the Mount Palomar Observatory in California in 2003.
A German group of researchers has now used a different form of analysis to more accurately gauge 2003 UB313’s diameter.
By measuring how much heat the planetoid radiates, the scientists led by Frank Bertoldi of the University of Bonn estimated that 2003 UB313 is about 1,864 miles across.
That makes it larger than Pluto, which has a diameter of about 1,429 miles.
“It is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status,” Bertoldi said in a statement.
Details were published in Thursday’s issue of the journal Nature.
Brown said the Germans’ measurement seemed plausible and said his team was using the Hubble Space Telescope to directly figure out its size.
He and his associates had originally reported that 2003 UB313 was thought to be larger than Pluto and estimated that it was most likely between 1,398 miles and 2,175 miles in diameter.
Among themselves, Brown, Trujillo and Rabinowitz have referred to the main body as “Xena,” after the sword-wielding syndicated TV warrior princess. The moon naturally has been called “Gabrielle,” after the TV Xena’s trusty sidekick.
Neither name is likely to stick, however. By convention, all new planets and Kuiper Belt objects are named after gods of various mythologies, and “Xena” and “Gabrielle” don’t qualify.
The previous contender for 10th planet, Quaoar, discovered by Brown, Trujillo and Rabinowitz in 2002, was named after the creator god of an American Indian tribe that lived in Southern California. It is about as far from the sun as Pluto is but has only one-third the mass.
Astronomers have been debating for several years over what a planet is and whether Pluto should keep its status.
A new model of the solar system at the American Museum of Natural History in New York leaves out Pluto, which prompted a letter-writing campaign from schoolchildren to reinstate the ninth planet when the permanent exhibit is unveiled.
The difficulty is that there is no official definition of a planet, and some argue that setting standards such as size limits would open the door too wide.
When the largest asteroids, Ceres, Vesta and Pallas, were discovered in the early 19th century, they were counted as planets until it became clear that they were part of a much larger belt of large rocks and planetoids ringing the Sun between Mars’ and Jupiter’s orbits.
Likewise, Pluto and Quaoar are part of the Kuiper Belt, an even larger ring of small objects orbiting the Sun beyond Neptune.
PASADENA, Calif. — Astronomers said Wednesday they have spotted evidence of two mega solar systems — giant stars enveloped by what appear to be huge disks of planet-forming dust.
Cloudy disks around stars are believed to represent current or future planetary systems. Our sun is surrounded by the Kuiper Belt, a disk containing dust, comets and other bodies.
Astronomers said the latest findings were surprising because such massive stars are thought to be inhospitable to the formation of planets.
“Our data suggest that the planet-forming process may be hardier than previously believed, occurring around even the most massive stars,” Joel Kastner, of the Rochester Institute of Technology, said in a statement.
Results appear in the Feb. 10 issue of the Astrophysical Journal Letters.
The new stars were measured to be 30 to 70 times more massive than the sun. Because of the stars’ size, scientists said the surrounding debris disks are larger versions of the Kuiper Belt and probably contain about 10 times more mass.
The new stars were found using NASA’s Spitzer Space Telescope during a survey of 60 bright stars. Kastner said the new discoveries stuck out from the rest because an analysis indicated the presence of flat disks.
Last year, another team of scientists discovered what they believe was a mini solar system. The team found a dust cloud around a brown dwarf, or failed star.
LOS ANGELES — Our solar system is suffering an identity crisis.
For decades, it has consisted of nine planets, even as scientists debated whether Pluto really belonged. Then the recent discovery of an object larger and farther away than Pluto threatened to throw this slice of the cosmos into chaos.
Should this newly found icy rock known as 2003 UB313 become the 10th planet? Should Pluto be demoted? And what exactly is a planet, anyway?
Ancient cultures regularly revised their answer to the last question and present-day scientists aren’t much better off: There still is no universal definition of “planet.”
That all could soon change, and with it science textbooks around this planet.
At a 12-day conference beginning Monday, scientists will conduct a galactic census of sorts. Among the possibilities at the meeting of the International Astronomical Union in the Czech Republic capital of Prague: Subtract Pluto or christen one more planet, and possibly dozens more.
“It’s time we have a definition,” said Alan Stern, who heads the Colorado-based space science division of the Southwest Research Institute of San Antonio. “It’s embarrassing to the public that we as astronomers don’t have one.”
The debate intensified last summer when astronomer Michael Brown of the California Institute of Technology announced the discovery of a celestial object larger than Pluto.
Like Pluto, it is a member of the Kuiper Belt, a mysterious disc-shaped zone beyond Neptune containing thousands of comets and planetary objects. (Brown nicknamed his find “Xena” after a warrior heroine in a cheesy TV series; pending a formal name, it remains 2003 UB313.)
The Hubble Space Telescope measured the bright, rocky object at about 1,490 miles in diameter, roughly 70 miles longer than Pluto. At 9 billion miles from the sun, it is the farthest known object in the solar system.
The discovery stoked the planet debate that had been simmering since Pluto was spotted in 1930.
Some argue that if Pluto kept its crown, Xena should be the 10th planet by default — it is, after all, bigger.
Purists maintain that there are only eight traditional planets, and insist Pluto and Xena are poseurs.
“Life would be simpler if we went back to eight planets,” said Brian Marsden, director of the astronomical union’s Minor Planet Center in Cambridge, Mass.
Still others suggest a compromise that would divide planets into categories based on composition, similar to the way stars and galaxies are classified. Jupiter could be labeled a “gas giant planet,” while Pluto and Xena could be “ice dwarf planets.”
“Pluto is not worthy of being called just a plain planet,” said Alan Boss, an astrophysicist at the Carnegie Institution in Washington, D.C. “But it’s perfectly fine as an ice dwarf planet or a historical planet.”
The number of recognized planets in the solar system has seesawed based on new findings. Ceres was initially classified as a planet in the 1800s, but was demoted to an asteroid when similar objects were found nearby.
Despite the lack of scientific consensus on what makes a planet, the current nine — and Xena — share common traits: They orbit the sun. Gravity is responsible for their round shape. And they were not formed by the same process that created stars.
Brown, Xena’s discoverer, admits to being “agnostic” about what the international conference decides. He said he could live with eight planets, but is against sticking with the status quo and would feel a little guilty if Xena gained planethood because of the controversy surrounding Pluto.
“If UB313 is declared to be the 10th planet, I will always feel like it was a little bit of a fraud,” Brown said.
For years, Pluto’s inclusion in the solar system has been controversial. Astronomers thought it was the same size as Earth, but later found it was smaller than Earth’s moon.
Pluto is also odd in other ways: With its elongated orbit and funky orbital plane, it acts more like other Kuiper Belt objects than traditional planets.
Even so, Pluto remained No. 9 because it was the only known object in the Kuiper Belt at the time.
When new observations in the 1990s confirmed that the Kuiper Belt was sprinkled with numerous bodies similar to Pluto, some scientists piped up. In 1999, the international union took the unusual step of releasing a public statement denying rumors that the ninth rock from the sun might be kicked out.
That hasn’t stopped groups from attacking Pluto’s planethood. In 2000, the Hayden Planetarium at New York’s American Museum of Natural History unleashed an uproar when it excluded Pluto as a planet in its solar system gallery.
Earlier this year, NASA’s New Horizons spacecraft began a 9˝-year journey to Pluto on a mission that scientists hope will reveal more about the oddball object.
The trick for astronomers meeting in Prague is to set a criterion that makes sense scientifically. Should planets be grouped by location, size or another marker? If planets are defined by their size, should they be bigger than Pluto or another arbitrary size?
The latter could expand the solar system to 23, 39 or even 53 planets.
It’s not an academic exercise — the public may not be open to a flood of new planets. Despite their differences, scientists agree any definition should be flexible enough to accommodate new discoveries.
“Science progresses,” said Boss of the Carnegie Institution. “Science is not something that’s engraved on a steel tablet never to be changed.”
PRAGUE, Czech Republic — It’s a cosmic clash, a space squabble, a mutiny in the Milky Way.
Leading astronomers are bitterly divided over new galactic guidelines that for the first time would define what is and isn’t a planet.
The debate all but dooms a proposal being put to a vote Thursday to expand the solar system to 12 planets from the traditional nine.
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Caught yet again in the crossfire is puny Pluto, scorned by many as a poser that could be demoted as a dwarf — slightly shrinking Earth’s neighborhood instead.
Opponents “smell blood, and I think they’re going to get it,” Alan Boss, an astrophysicist at the Carnegie Institution in Washington, D.C., said on the eve of a vote by members of the International Astronomical Union.
Leaders of the group, the official arbiter of heavenly bodies, caused a sensation last week by proposing that Pluto’s largest moon and two other objects officially be designated as planets. They suggested that Pluto and the three newcomers be the first of a new class of planet dubbed “plutons.”
The rationale was their initial draft definition of a planet: any object larger than nearly 500 miles in diameter that orbits the sun, has a mass roughly one-12,000th that of Earth and has enough self-gravity to pull itself into a round shape.
But for many of the 2,500 astronomers from 75 countries meeting in Prague, the universe hasn’t been the same since.
After days of spirited and sometimes combative debate, renegade scientists have won some key concessions.
A planet, they insist, must be the dominant object in its area. That would draw a sharp distinction between the eight “classical planets” — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune — and Pluto, which would be known as a “dwarf planet.”
Pluto’s largest moon, Charon, the asteroid Ceres, which was a planet in the 1800s before it got demoted, and a recently discovered object known as 2003 UB313 and nicknamed Xena also would be dwarfs.
The precise wording of the definition remained a work in progress Wednesday.
However, if astronomers agree that a planet must have “orbital dominance” in its own neighborhood, the new guidelines would eliminate Pluto and the trio of tentative candidates as proper planets.
“It’s a kind of compromise: There would be only eight planets, plus the dwarf planets,” said Japanese astronomer Junichi Watanabe, a member of the IAU’s planet definition committee.
Many believe there’s simply no scientific justification to grant full planet status to most of what’s floating in the vast sea of rocks that reside in the Kuiper Belt — a mysterious, disc-shaped zone beyond Neptune containing thousands of comets and planetary objects.
“It’s impossible to draw the line between the new dwarf planets and large asteroids,” said Mark Bailey, director of Britain’s Armagh Observatory.
And forget the term “pluton” — it’s already history.
Under pressure from a growing faction of astronomers, the planet definers have been tossing around other options: plutoids, plutonids, plutonoids, plutians, or Tombaugh objects or planets in honor of Clyde Tombaugh, the American who discovered Pluto in 1930.
Among the scientists who torpedoed “pluton” were geologists, who pointed out — somewhat embarrassingly to astronomers — that it’s already a prominent term in volcano science for deep igneous rock formations.
“What were they thinking? The reaction in the geologic community was rolling of eyes,” said Allen F. Glazner, a geologist at the University of North Carolina. “It would be like botanists trying to distinguish between trees and shrubs and coming up with the term ‘animal.’”
Harvard’s Owen Gingerich, who chairs the planet definition panel, conceded: “We perhaps stumbled.”
After the panel got dozens of objecting e-mails, “we backed off,” he added.
Suddenly, the future looks dim for much-maligned Pluto, which is smaller than Earth’s moon.
Its underdog status has inspired scores of tributes, including one by New York folk singer Christine Lavin that laments: “I guess if Pluto showed up at a planet convention, the bouncer at the door might have to ban it.”
“Some say, ‘No, Pluto is a nice planet’” and should remain one, Watanabe said.
“It’s an important object that has played an important role,” he said. “But this is a natural way to draw a line.”
PRAGUE, Czech Republic — It’s smaller than Earth’s moon, has a funky way of orbiting the sun, and lurks so far out on the fringes of the solar system even the powerful Hubble Space Telescope has to squint to see it.
Pluto is no stranger to controversy. In fact, it’s been dogged by disputes ever since its discovery in 1930.
Many astronomers contend the ninth rock from the sun — which faced the prospect of being demoted to “dwarf planet” status Thursday if the International Astronomical Union approves a new definition for planets — never deserved to be one in the first place.
Discovered by Clyde Tombaugh of Arizona’s Lowell Observatory, Pluto was classified as a planet because scientists initially believed it was the same size as Earth.
It remained one because for years, it was the only known object in the Kuiper Belt, an enigmatic zone beyond Neptune that’s teeming with comets and other planetary objects.
Pluto got an ego boost in 1978 when it was found to have a moon that was later named Charon. The Hubble turned up two more, which this past June were christened Nix and Hydra.
But in the 1990s, more powerful telescopes revealed numerous bodies similar to Pluto in the neighborhood. New observations also showed that Pluto’s orbit was oblong, sending it soaring well above and beyond the main plane of the solar system where Earth and the other seven planets circle the sun.
That prompted some galactic grumbling from astronomers who began openly attacking Pluto’s planethood.
At one point, things looked so bad for Pluto, the international union said publicly in 1999 that rumors of Pluto’s imminent demise were greatly exaggerated and there were no plans to kick it out of the cosmic club.
A year later, the Hayden Planetarium at New York’s American Museum of Natural History was accused of snubbing Pluto by excluding it from a solar system exhibition.
Pluto took another hit after Michael Brown of the California Institute of Technology discovered 2003 UB313, a slightly larger Kuiper Belt object. What’s the point, some astronomers wondered, in keeping Pluto as a planet?
Its future brightened earlier this year, when NASA sent the New Horizons spacecraft to Pluto to get a closer look at the ball of rock and ice. The Hubble has managed to glimpse only its most prominent surface features; New Horizons, if all goes well, will arrive in 2015.
As recently as last week, the IAU — the official arbiter of heavenly bodies — appeared ready to reaffirm Pluto’s planet status.
Richard Binzel, a professor of planetary science at the Massachusetts Institute of Technology and a member of the international union’s planet definition committee, had contended that Pluto met key tests of planetary physics “by a long shot” and had earned its status.
On Thursday, looking weary, he was asked whether he’ll mourn if Pluto winds up demoted.
“I don’t know. Ask me later,” he said.
By Seth Borenstein, Associated Press
Astronomers have discovered a planet outside our solar system that is potentially habitable, with Earth-like temperatures, a find researchers described yesterday as a big step in the search for “life in the universe.”
The planet is just the right size, might have water in liquid form, and in galactic terms is relatively nearby at 120 trillion miles away. But the star it closely orbits, known as a “red dwarf,” is much smaller, dimmer and cooler than our sun.
There’s still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is known about it. And it’s worth noting that scientists’ requirements for habitability count Mars in that category: a size relatively similar to Earth’s with temperatures that would permit liquid water. However, this is the first outside our solar system that meets those standards.
“It’s a significant step on the way to finding possible life in the universe,” said University of Geneva astronomer Michel Mayor, one of 11 European scientists on the team that found the planet. “It’s a nice discovery. We still have a lot of questions.”
The results of the discovery have not been published but have been submitted to the journal Astronomy & Astrophysics.
Alan Boss, who works at the Carnegie Institution of Washington where a U.S. team of astronomers competed in the hunt for an Earth-like planet, called it “a major milestone in this business.”
The planet was discovered by the European Southern Observatory’s telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wavelengths. Those wobbles can reveal the existence of other worlds.
What they revealed is a planet circling the red dwarf star, Gliese 581. Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun. Until a few years ago, astronomers didn’t consider these stars as possible hosts of planets that might sustain life.
The discovery of the new planet, named 581c, is sure to fuel studies of planets circling similar dim stars. About 80% of the stars near Earth are red dwarfs.
The new planet is about five times heavier than Earth. Its discoverers aren’t certain whether it is rocky like Earth or whether it is a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 1? times bigger than our planet. If it is an ice ball, as Mr. Mayor suggests, it would be even bigger.
Based on theory, 581c should have an atmosphere, but what’s in that atmosphere is still a mystery and if it’s too thick that could make the planet’s surface temperature too hot to support life, Mr. Mayor said.
However, the research team thinks the average temperature to be somewhere between 32 and 104 degrees and that set off celebrations among astronomers.
Until now, all 220 planets astronomers have found outside our solar system have had the “Goldilocks problem.” They’ve been too hot, too cold or just plain too big and gaseous, such as uninhabitable Jupiter.
The new planet seems just right — or at least that’s what scientists think.
“This could be very important,” said NASA astrobiology specialist Chris McKay, who was not part of the discovery team. “It doesn’t mean there is life, but it means it’s an Earth-like planet in terms of potential habitability.”
Besides having the right temperature, the new planet is probably full of liquid water, says Geneva astronomer Stephane Udry, the discovery team’s lead author. But that is based on theory about how planets form, not on any evidence, he said.
“Liquid water is critical to life as we know it,” said co-author Xavier Delfosse of Grenoble University in France. “Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the universe, one would be tempted to mark this planet with an X.”
Other astronomers cautioned it’s too early to tell whether there is water.
“You need more work to say it’s got water or it doesn’t have water,” said retired NASA astronomer Steve Maran, press officer for the American Astronomical Society. “You wouldn’t send a crew there assuming that when you get there, they’ll have enough water to get back.”
The new planet’s star system is a mere 20.5 light years away, making Gliese 581 one of the 100 closest stars to Earth. It’s so dim, you can’t see it without a telescope, but it’s somewhere in the constellation Libra, which is low in the southeastern sky during the midevening in the Northern Hemisphere.
Before you book your extrastellar flight to 581c, a few caveats about how alien that world probably is: Anyone sitting on the planet would get heavier quickly, and birthdays would add up fast since it orbits its star every 13 days.
Gravity is 1.6 times as strong as Earth’s, so a 150-pound person would feel like 240 pounds.
And it’s likely, but still not known, that the planet doesn’t rotate, so one side would always be sunlit and the other dark.
Distance is another problem. “We don’t know how to get to those places in a human lifetime,” Mr. Maran said.
Astronomers have obtained the first images of an asteroid that made its closest approach to Earth on Tuesday, showing the space rock is lopsided.
The new images, taken with the Goldstone Solar System Radar Telescope in California’s Mojave Desert, refine estimates of the asteroid’s size.
Named 2007 TU24, the asteroid was estimated to span up to 2,000 feet (610 meters), but is now thought to have a diameter of about 800 feet (250 meters).
Scientists at NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif., have determined that there is no possibility of an impact with Earth in the foreseeable future.
Other radar telescopes pointed toward the asteroid as it made its closest approach to Earth, 334,000 miles (537,500 kilometers), at 3:33 a.m. Eastern time Jan. 29.
For comparison, the moon is an average of 239,228 miles (385,000 kilometers) away.
At its nearest, the asteroid reached an approximate apparent magnitude 10.3, or about 50 times fainter than an object visible to the naked eye in a clear, dark sky.
Then it quickly got fainter as it moved away.
The combination of these telescopes, including the Arecibo Observatory in Puerto Rico, will provide higher resolution images of the asteroid.
Measurements from Arecibo’s radar telescope will gauge the object’s size more precisely, its speed and spin.
The Arecibo Observatory is operated by Cornell University on behalf of the National Science Foundation.
Like other asteroids, this one orbits the sun. Most do so in the asteroid belt between Mars and Jupiter. NASA pays particular attention to those whose orbits bring them so close to Earth.
TU24, discovered by NASA’s Catalina Sky Survey on Oct. 11, 2007, is one of an estimated 7,000 near-Earth objects identified to date (another 7,000 are estimated to exist but are yet to be discovered).
“We have good images of a couple dozen objects like this, and for about one in 10, we see something we’ve never seen before,” said Mike Nolan, head of radar astronomy at the Arecibo Observatory. “We really haven’t sampled the population enough to know what’s out there.”
Astronomers said Wednesday that they had found a miniature version of our own solar system 5,000 light-years across the galaxy — the first planetary system that really looks like our own, with outer giant planets and room for smaller inner planets.
“It looks like a scale model of our solar system,” said Scott Gaudi, an assistant professor of astronomy at Ohio State University. Gaudi led an international team of 69 professional and amateur astronomers who announced the discovery in a news conference with reporters.
Their results are being published Friday in the journal Science. The discovery, they said, means that our solar system may be more typical of planetary systems across the universe than had been thought.
In the newly discovered system, a planet about two-thirds of the mass of Jupiter and another about 90% of the mass of Saturn are orbiting a reddish star at about half the distances that Jupiter and Saturn circle our own Sun. The star is about half the mass of the Sun.
Neither of the two giant planets is a likely abode for life as we know it. But, Gaudi said, warm rocky planets — suitable for life — could exist undetected in the inner parts of the system.
“This could be a true solar system analogue,” he said.
Sara Seager, a theorist at the Massachusetts Institute of Technology who was not part of the team, said that “right now in exoplanets we are on an inexorable path to finding other Earths.” Seager praised the discovery as “a big step in finding out if our planetary system is alone.”
Since 1995, around 250 planets outside the solar system, or exoplanets, have been discovered. But few of them are in systems that even faintly resemble our own. In many cases, giant Jupiter-like planets are whizzing around in orbits smaller than that of Mercury. But are these typical of the universe?
Almost all of those planets were discovered by the so-called wobble method, in which astronomers measure the gravitational tug of planets on their parent star as they whir around it. This technique is most sensitive to massive planets close to their stars.
The new discovery was made by a different technique that favors planets more distant from their star. It is based on a trick of Einsteinian gravity called microlensing. If, in the ceaseless shifting of the stars, two of them should become almost perfectly aligned with Earth, the gravity of the nearer star can bend and magnify the light from the more distant one, causing it to get much brighter for a few days.
If the alignment is perfect, any big planets attending the nearer star will get into the act, adding their own little boosts to the more distant starlight.
That is exactly what started happening on March 28, 2006, when a star 5,000 light-years away in the constellation Scorpius began to pass in front of one 21,000 light-years more distant, causing it to flash. That was picked up by the Optical Gravitational Lensing Experiment, or Ogle, a worldwide collaboration of observers who keep watch for such events.
Ogle in turn immediately issued a worldwide call for continuous observations of what is now officially known as OGLE-2006-BLG-109. The next 10 days, as Andrew Gould, a professor of mathematical and physical sciences at Ohio State said, were “extremely frenetic.”
Among those who provided crucial data and appeared as lead authors of the paper in Science were a pair of amateur astronomers from Auckland, New Zealand, Jennie McCormick and Grant Christie, both members of a group called the Microlensing Follow-Up Network, or MicroFUN.
Somewhat to the experimenters’ surprise, by clever manipulation they were able to dig out of the data not just the masses of the interloper star and its two planets, but also rough approximations of their orbits, confirming the similarity to our own system. David Bennett, an assistant professor of astrophysics at the University of Notre Dame, said, “This event has taught us that we were able to learn more about these planets than we thought possible.”
As a result, microlensing is poised to become a major new tool in the planet hunter’s arsenal, “a new flavor of the month,” Seager said.
Only six planets, including the new ones, have been discovered by microlensing so far, and the Scorpius event being reported Friday is the first in which the alignment of the stars was close enough for astronomers to detect more than one planet at once. Their success at doing just that on their first try bodes well for the future, astronomers say.
Alan Boss, a theorist at the Carnegie Institution of Washington, said, “The fact that these are hard to detect by microlensing means there must be a good number of them — solar system analogues are not rare.”
Earth may have a twin orbiting one of our nearest stellar neighbors, a new study suggests.
University of California, Santa Cruz graduate student Javiera Guedes used computer simulations of planet formation to show that terrestrial planets are likely to have formed around one of the stars in the Alpha Centauri star system, our closest stellar neighbors.
Guedes’ model showed planets forming around the star Alpha Centauri B (its sister star, Proxima Centauri, is actually our nearest neighbor) in what is called the “habitable zone,” or the region around a star where liquid water can exist on a planet’s surface.
The model also showed that if such planets do in fact exist, we should be able to see them with a dedicated telescope.
“If they exist, we can observe them,” Guedes said.
Guedes’ study has been accepted for publication in the Astrophysical Journal.
A likely candidate
Astronomers have for some time pinned the Alpha Centauri system as one that was likely to form planets, said study co-author Gregory Laughlin, a UCSC professor.
“I think that there’s been a good line of evidence over the past decade or so,” Laughlin told SPACE.com.
Several factors mark the system, particularly Alpha Centauri B as friendly to planet formation, Laughlin said.
The metallicity of Alpha Centauri B (or how much of its matter is made up of elements heavier than hydrogen and helium) is higher than our Sun’s, so there would be plenty of heavier-mass material for planets to form from, he said.
Also, because the planet is a triple star system, the processes that form large Jupiter-mass gas giants, which account for most of the extrasolar planets found so far, would be suppressed. So it would be more likely for the system to produce terrestrial planets.
Laughlin also noted that a number of factors make Alpha Centauri B a good candidate for astronomers to actually detect an Earth-sized terrestrial planet.
The Doppler detection method, which has revealed the majority of the 228 known extrasolar planets, measures shifts in the light from a star to detect the tiny wobble induced by the gravitational tug of an orbiting planet.
Because Alpha Centauri B is so bright and nearby, detecting a small terrestrial planet’s miniscule wobble would be that much easier. Also, its position high in the sky of the Southern Hemisphere means it is observable for most of the year, just as the Big Dipper is observable for most of the year in the Northern Hemisphere.
According to Laughlin, five years of observations using a dedicated telescope would be needed to detect an Earth-like planet around Alpha Centauri B. If astronomers do dedicate substantial resources to detecting an Earth-like planet, this is the star to focus on, he added.
“We’re advocating that there’s a strong possibility a planet could be there,” he said.
Other stars are thought to harbor Earth-like planets, and solar systems like ours are starting to be found. Astronomers announced last month the discovery of a solar system with striking similarities to ours.
If such a planet is found, spacecraft, such as the proposed Terrestrial Planet Finder, could be launched to find out more information about the world, such as whether or not it had water on its surface, Laughlin said.
Study co-author Debra Fischer of San Francisco State University is leading an observational program to intensively monitor Alpha Centauri A and B using the 1.5-meter telescope at the Cerro Tololo Inter-American Observatory in Chile. The researchers hope to detect real planets similar to the ones that emerged in the computer simulations.
“I think the planets are there, and it’s worth a try to have a look,” Laughlin said.
Planet hunters say it’s just a matter of time before they lasso Earth’s twin, which almost surely is hiding somewhere in our star-studded galaxy.
Momentum is building: Just last week, astronomers announced they had discovered three super-Earths — worlds more massive than ours but small enough to most likely be rocky — orbiting a single star. And dozens of other worlds suspected of having masses in that same range were found around other stars.
“Being able to find three Earth-mass planets around a single star really makes the point that not only may many stars have one Earth, but they may very well have a couple of Earths,” said Alan Boss, a planet formation theorist at the Carnegie Institution of Washington in Washington, D.C.
Since the early 1990s, when the first planets outside of our solar system were detected orbiting the pulsar PSR 1257, astronomers have identified nearly 300 such worlds.
However, most of them are gas giants called “hot Jupiters” that orbit close to their stars because, simply, they are easier to find.
“So far we’ve found Jupiters and Saturns, and now our technology is becoming good enough to detect planets smaller, more like the size of Uranus and Neptune, and even smaller,” said one of the top planet hunters on this world, Geoff Marcy of the University of California, Berkeley.
Marcy, Boss and other scientists are optimistic that within the next five or so years headlines will be splashed with news of a near twin of Earth in another star system.
“What is amazing to me is that for thousands of years humans have gazed at the stars, wondering if there might be another Earth out there somewhere,” Boss told SPACE.com. “Now we know enough to say that Earth-like planets are indeed orbiting many of those stars, unseen perhaps, but there nevertheless.”
Seeing tiny planets
Two techniques are now standard for spotting other worlds. Most of the planets noted to date have been discovered using the radial velocity method, in which astronomers look for slight wobbles in a star’s motion due to the gravitational tug of an orbiting planet. This favors detection of very massive planets that are very close to their host stars.
With the transit method, astronomers watch for a dimming of light when a planet passes in front of its host star. Though more haphazard, this approach works when telescopes scan the light from hundreds or thousands of stars at once.
Both methods are limited by their ability to block out the overshadowing light of the host star. For instance, the sun is 100 times larger, 300,000 times more massive and up to 10 billion times brighter than Earth.
“Detecting Earth in reflected light is like searching for a firefly six feet from a searchlight that is 2,400 miles distant,” writes a panel of astronomers recently in their final report of the Exoplanet Task Force.
With upgrades in spectrometers and digital cameras attached to telescopes, astronomers’ eyes have become more sensitive to relatively tiny stellar wobbles (measured by changes in certain wavelengths of light) and dips in starlight from ever smaller planets.
The discovery of super-Earths announced last week reflects this technological leap.
“I think why astronomers are really excited [about the super-Earth discovery] is it just shows that technology has really matured and so they’re able to see these very subtle wobbles due to these low-mass planets,” said David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Massachusetts. “Those were fairly massive stars. If they were able to get the same precision on a lower-mass star, they would be able to look at even lower-mass planets and so those really would be analogs of the Earth.”
The fast track
To eke out even more sensitivity from current technologies, Charbonneau suggests astronomers look for worlds around small stars.
He and other astronomers are in fact probing the universe for transiting planets orbiting M dwarfs, or red dwarfs, which are about 50% dimmer than the sun and much less massive. Red dwarfs are also considered the most common star type in the universe.
“I think the real opportunity there is to study low-mass stars, and that’s because we’re looking for very small planets,” Charbonneau said. “The difficulty is the ratio between the planet’s mass and the star’s mass or the planet’s size and the star’s size depending on how you want to find it.”
The low mass and luminosity means any changes to the star due to an Earth-mass planet are much more likely to be detected.
“A late-M star is about 10 times smaller than the sun,” said Penn State’s James Kasting, who studies planetary atmospheres and the habitable zones of exoplanets. “So Earth going in front of an M star would give a 1% signal. That’s like Jupiter going in front of the sun.”
Kasting added, “We could conceivably find an Earth-analog planet by this method within the next five or ten years.”
Other teams are gearing up to look for Earth-like worlds orbiting massive stars like the sun. NASA’s Kepler observatory is scheduled for launch in February 2009, after which the high-powered telescope will monitor about 100,000 stars in the Milky Way looking for periodic dimming of starlight due to a planet’s transit in front of the star.
The French COROT mission is already up in space working in a similar fashion.
The ultimate goal of planet-hunting projects is to find Earth twins.
“We are looking for twins of the Earth, analogs that walk and talk and smell like our own Earth,” Marcy said during a telephone interview.
He is currently looking for super-Earths using the W.M. Keck Observatory in Hawaii.
Such a twin would be rocky, with a similar chemical composition to Earth, and would orbit within the habitable zone of its star.
The habitable zone defines the distance at which a planet must orbit from its star for liquid water to exist on its surface — not too hot like Venus, not too cold like Neptune or Pluto.
Astronomers have found planets orbiting pretty close to the habitable zone, but none so far within it.
“I suspect there are Earth-like planets with lakes and rivers and waterfalls and deep glacial gorges and that are spectacularly beautiful,” Marcy said.
Life beyond Earth
Finding a planet in the habitable zone is the first step toward finding alien life.
“When we say it’s a habitable world, all we’re doing is saying it potentially could hold life,” Boss said. “To go beyond that to say, ‘Here’s a habitable world; is it inhabited?,’ then you need to start studying the atmosphere of the planet.”
The James Webb Space Telescope (JWST), scheduled for launch in 2013, could do just that.
“There might be a signal in the atmosphere that could be a smoking gun and would suggest that plate tectonics is there,” said earth and planetary scientist Diana Valencia of Harvard University.
Her computer models have shown that plate tectonics, the forces that move continents and lift gigantic mountain ranges, are key to life on Earth as we know it, and possibly to life on other worlds.
That’s because as the rocky plates that form the planet’s outer shell move about, they also recycle carbon dioxide. This greenhouse gas keeps our planet’s temperature balmy, but not too hot.
The telltale signal would be certain levels of carbon dioxide, suggesting that just as on Earth, this other world relies on plate tectonics to cycle carbon.
But first things first.
“There’s no doubt that other Earths exist, simply due to the sheer vast numbers of other stars and galaxies in our universe,” Marcy said. “There’s a deeper question — how common are Earth-like planets? Are Earth-like planets a dime a dozen, or are they quite rare, quirky precious planets that are one in a thousand or one in a million?”
CAPE CANAVERAL, Fla. — Scientists have exposed some of the mystery behind the northern lights.
On Thursday, NASA released findings that indicate magnetic explosions about one-third of the way to the moon cause the northern lights, or aurora borealis, to burst in spectacular shapes and colors, and dance across the sky.
The findings should help scientists better understand the more powerful but less common geomagnetic storms that can knock out satellites, harm astronauts in orbit and disrupt power and communications on Earth, scientists said.
A fleet of five small satellites, called Themis, observed the beginning of a geomagnetic storm in February, while ground observatories in Canada and Alaska recorded the brightening of the northern lights.
The southern lights — aurora australis — also brightened and darted across the sky at the same time.
These auroral flare-ups occur every two or three days, on average.
A team led by University of California, Los Angeles, scientist Vassilis Angelopoulos confirmed that the observed storm about 80,000 miles from Earth was triggered by a phenomenon known as magnetic reconnection.
Every so often, the Earth’s magnetic field lines are stretched like rubber bands by solar energy, snap, are thrown back to Earth and reconnect, in effect creating a short circuit.
It’s this stored-up energy that powers the northern and southern lights or, in other words, causes them to dance, according to Angelopoulos.
An opposing theory has these geomagnetic events occurring much closer to Earth, about one-sixth of the way to the moon. More Themis observations are needed to resolve the debate, said David Sibeck, NASA’s project scientist.
“Finally, we have the right instruments in the right place at the right time, and it’s allowed scientists to be able to make the necessary observations to settle this heated debate once and for all,” said Nicola Fox, a Johns Hopkins University scientist who was not involved in the study.
At present, about 20 of these geomagnetic storms are being analyzed. Scientists hope to eventually learn, via this project, more about the bigger solar storms that occur about 10 times a year and can lead to far more expansive and prolonged northern and southern lights.
The five Themis spacecraft — a NASA acronym standing for Time History of Events and Macroscale Interations during Substorms — were launched aboard a single rocket last year.
Eager to answer the question of what’s hiding out in the cold darkness of space, a team of U.S. physicists is eyeing a move to a subterranean warren of laboratories two kilometres down a mine shaft near Sudbury, Ont., that has quickly become a world destination for “dark matter” researchers.
The U.S.-based Cryogenic Dark Matter Search (CDMS) team is seeking funding to expand its work and relocate the project from an underground laboratory in Minnesota to Sudbury’s SNOLAB, one of the researchers revealed at a physics conference in Paris over the weekend.
There they would join other researchers already drawing closer to answers about a nagging, crucial mystery regarding the nature of the universe, and the odds are improving that Sudbury will witness a significant breakthrough.
SNOLAB, the world’s deepest physics lab, sits at the centre of an intensifying worldwide search for conclusive evidence of dark matter — shadowy, theoretical stuff that is extremely difficult to detect even while many physicists believe its gravitational tug pulled the stars and galaxies into existence.
“There’s certainly the strong possiblity that Sudbury can discover these things,” said Fraser Duncan, SNOLAB’s associate director of operations, in an interview on Monday. “It’s absolutely safe to say that SNOLAB is at the forefront of this very competitive field. The facility we have is the best operational facility for doing this physics.”
The CDMS research group will need to receive US$4-million in annual funding from the U.S. government and other sources in order to proceed with the experiment by around 2013.
Like other experiments already underway at SNOLAB, the CDMS project will try to detect weakly interacting massive particles, or WIMPs: shadowy particles that have so far never been observed, but may account for the 80% of the matter in the universe that is believed to be “dark.”
Swiss physicist Fritz Zwicky proposed the existence of dark matter in 1934 after he observed that galaxies spin faster than they ought to, given the matter that is actually detectable. Dark matter does not emit, reflect or absorb light, making it difficult to observe. What it does have are mass and gravitational properties, which are believed to have acted as a glue to mould ordinary matter into planets to galaxies.
“You’re looking for something that we don’t know is there. We don’t know for a fact that dark matter exists, but there’s very good circumstantial evidence for it. That’s why a lot of us are putting a lot of effort into looking for it,” Dr. Duncan said.
Even if particle physicists do not know for sure what dark matter is composed of, WIMPs represent the leading candidate for what they could be. The last decade has seen an enthusiasm for experimentation in this direction, and the SNOLAB complex has expanded deeper into the rock of Northern Ontario in response.
The great challenge in the hunt for WIMPs is the risk of mistaking everyday background cosmic radiation for a brush with dark matter. The unique rock shielding of SNOLAB makes it an ideal place to seek protection from that radiation.
The CDMS research group looking to relocate its experiments to Canada will use hockey puck-like crystals of germanium to detect WIMPs passing by.
“Sometimes it’s summed up that we’re the best in the world at seeing nothing,” said Richard Schnee, a Syracuse University physics professor who acts as principal investigator on the CDMS project. “For the SNOLAB phase, the goal would be a factor of 100 better than the sensitivity that we’ve achieved so far.”
The SNOLAB complex uses the infrastructure of the Vale/Inco Creighton Mine (which is still actively extracting nickel, following a nearly year-long strike by workers that ended this month). SNOLAB is supported by a number of government innovation funds and already has two other major dark matter projects underway: the Project In Canada to Search for Supersymmetric Objects, or PICASSO, currently under way; and Dark Matter Experiment using Argon Pulse, or DEAP, which is now in a prototype phase.
SNOLAB will get busier over the next few years. It offers capacity for three or four large competing experiments, and several smaller-scale ones, to be run simultaneously. Each dark matter research team located or planning to locate at SNOLAB is using a different technique in the race to prove the existence of WIMPs.
Whichever is successful — if any — Dr. Schnee of the CDMS project said what is at stake is an improved picture of our universe.
“I wouldn’t particularly expect that there would be practical applications. However, our understanding of the universe would be significantly changed,” he said. “Most of the mass in the universe, we don’t know what it is. It might be WIMPs, it might be something else.”
Alien life has been among us all along, according to new biological findings announced by NASA Thursday.
Research conducted by biochemist Dr. Felisa Wolfe-Simon from the U.S. Geological Survey has turned the quest for alien life on its ear, suggesting that phosphorous, carbon, and the other fundamental elements found in every living thing on Earth aren’t the only signs of life. Wolfe-Simon will explain the findings at a hotly anticipated NASA press conference today at 2 p.m.
After a two-year study at California’s Mono Lake, near Yosemite National Park, Wolfe-Simon found that a bug will grow in the presence of the toxic chemical arsenic when only slight traces of phosphorous are present. It’s a radical finding, says molecular biologist Steven Benner, who is part of NASA’s “Team Titan” and an expert on astrobiology — forcing the space agency to redefine the quest for other life in the universe.
“When we’re searching for alien life, if it’s not a Ferengi from Star Trek, what would it be?” Benner asked FoxNews.com. In his estimation, we’ve always defined life as something that has the exact same chemistry as a life-form on Earth. The new discovery will likely change that equation, because it means the basic building blocks of DNA are not quite what we thought.
Benner, said the arsenic-loving organism at Mono Lake grew without high levels of the nutrient phosphate (although some phosphates were still present). Just as important, it could change how we look for alien life on other planets, especially on Saturn and the moons of Jupiter.
“It’s a paradigm shift,” says Dimitar Sasselov, an astrobiologist who leads the Origins of Life Initiative at Harvard University. “The possibility that Earth-life biochemistry is not universal is a transformational concept. It fills the search [for alien life] with optimism. NASA is moving in a good overall direction. What is needed is to take alternatives for life’s chemistry to heart and fund research work better.”
Arsenic is poisonous to nearly all forms of life on earth. Even small amounts of the poison become embedded in living tissue, causing liver failure and ultimately death — in nearly everything BUT these bacteria.
However, as science fiction author Robert Sawyer told FoxNews.com, there could be even more profound implications. We have always looked for alien life that matches our biology, but now we have found a different life-form that uses arsenic in its basic DNA structure, he said.
Sawyer explained that NASA science probes have always looked in the most likely places we thought life could exist — on Mars or Europa, a moon of Jupiter. There is an old joke, he says, about how someone lost a quarter in their garage, then looks out in the yard for it. A neighbor asks why they are looking there instead of in the garage; the light is better, he answers.
“We tend to use the tools we know and the places we know to look for alien life,” Sawyer said, explaining that humans want to find a walking, crawling alien and not one that just has different DNA.
The change, he says, is that NASA will start looking for arsenic as well, and possibly other chemicals. This could mean new missions to Titan, which is known for having traces of arsenic. Another change could be the scientific equipment we send to space – probes might be retrofitted to search for arsenic.
Benner said the finding even impacts earlier research. Several years ago, when a Martian meteorite crash-landed on Earth, scientists examined it for the presence of phosphates. Now, it may be possible to re-visit some of the earlier findings. This hints at what experts call the “shadow biosphere” — the existence of other life-forms, even on Earth, that have a radically different DNA structure.
“It’s a huge breakthrough. It changes the probabilities for their being life on other planets,” Sawyer told FoxNews.com. “If there is more than one recipe that makes life, then there are chances of rolling the dice in a chemical soup of all over the universe, and the chances of that chemical soup giving rise to life is much larger.”
For NASA, the scientific discovery could help the agency acquire new funding
, serving as a catalyst to convince Congress to green light for new missions to Mars or Titan.
In fact, the Internet buzz about finding alien life, as Sawyer noted, is partly due to how NASA has timed the announcement. A new Congress means new opportunities for scientific missions. He says the reality of the finding is somewhat of a joykill — we have not found E.T. — but there are still major implications for science and the search for extra-terrestrial life in our solar system and beyond.
Benner says the findings need further review — there are questions about how much phosphorous is needed to sustain life.
“The next phase is to grow more of the stuff in a lab using a defined cultured, maybe cook up a broth that contains no phosphorous at all, look at this with a critical eye,” he said.
However you view the announcement, the Lake Mono findings are profound, and the possibilities for finding life — especially the primordial kind — are now even greater.
Astronomers have confirmed the first discovery of an alien planet in our Milky Way that came from another galaxy, they announced Thursday.
The Jupiter-like planet orbits a star that was born in another galaxy and later captured by our own Milky Way sometime between 6 billion and 9 billion years ago, researchers said. A side effect of the galactic cannibalism brought a faraway planet within astronomers’ reach for the first time ever.
“This is very exciting,” said study co-author Rainer Klement of the Max-Planck-Institut fur Astronomie (MPIA) in Heidelberg, Germany. “We have no ability to directly observe stars in foreign galaxies for planets and confirm them.”
Stars currently residing in other galaxies are simply too far away, Klement added.
The find may also force astronomers to rethink their ideas about planet formation and survival, researchers said, since it’s the first planet ever discovered to be circling a star that is both very old and extremely metal-poor. Metal-poor stars are lacking in typically lack elements heavier than hydrogen and helium.
The newfound planet, called HIP 13044b, survived through its star’s red-giant phase, which our own sun will enter in about 5 billion years. So studying it could offer clues about the fate of our solar system as well, researchers said.
HIP 13044b sits extremely close to its parent star, which has now contracted again. The planet completes an orbit every 16.2 days, and it comes within about 5 million miles (8 million kilometers) of its parent star at closest approach — just 5.5% of the distance between Earth and the sun.
Searching for telltale tugs
The newly discovered alien planet is at least 25% more massive than Jupiter, researchers said. It orbits the star HIP 13044 about 2,000 light-years from Earth in the constellation Fornax.
HIP 13044 is about as massive as the sun, and it is nearing the end of its life. The star has already gone through its red giant phase — when sun-like stars bloat enormously after exhausting the hydrogen fuel in their cores.
The star is also composed almost entirely of hydrogen and helium. It is less than only 1% as metal-rich as our sun, making it the most metal-poor star known to host a planet, researchers said.
The research team scrutinized HIP 13044’s movement using a telescope at the European Southern Observatory’s La Silla Observatory in Chile. After six months of observing, they detected tiny movements that betrayed the gravitational tug of an orbiting planet.
“For me, it was a big surprise,” said study lead author Johny Setiawan, also of MPIA. “I was not expecting it in the beginning.”
Setiawan, Klement and their colleagues report their results online in the Nov. 18 issue of Science.
An extragalactic origin
Last year, another research team announced it may have detected a planet in the Andromeda galaxy. However, that faraway find will be nearly impossible to confirm.
The astronomers performing that previous study used a method called gravitational microlensing, which only works when a planet-hosting star happens to line up with another star. Such events happen very rarely.
HIP 13044, on the other hand, belongs to the Helmi stream of stars that were once part of a nearby dwarf galaxy. Astronomers believe our own Milky Way gobbled up the Helmi stream between 6 billion to 9 billion years ago.
While it’s technically possible that the planet was born in the Milky Way and then stripped from its parent star by the interloping HIP 13044, the odds of that happening are minuscule, researchers said.
So HIP 13044 almost certainly has an extragalactic origin.
“We can be pretty sure about that,” Klement told SPACE.com. “Stellar encounters in the Milky Way essentially don’t occur. The chance that the star captured the planet from another star by an encounter is very, very unlikely.”
Rethinking theories of planet formation
Most of the nearly 500 alien planets discovered so far orbit metal-rich stars, researchers said. And a metal-rich star is fundamental to the dominant theory explaining how giant planets form — the core-accretion model.
This model posits that dust and gas particles circling a young star cling together and gradually become larger, forming rocks, boulders and eventually the stony cores of giant, gassy planets like HIP 13044b.
Because its parent star is so metal-poor, HIP 13044b may have formed in a different way, researchers said. The planet may have arisen via the gravitational attraction between gas molecules, through a process termed the disk-instability model. So it may not have a rocky core at all.
“You are able to form pure gas planets by this method,” Klement said.
The fact that such a metal-poor star can host planets should inspire astronomers to look at other stars like it, Klement added. Astronomers haven’t examined many up to this point, so they don’t have a good handle on how frequently planets might pop up around low-metal stars.
The discovery also hints that planets may have studded the cosmos from the universe’s early days — back when pretty much all stars were metal-poor.
“You can think of the very first stars in the universe, or the second or third generation of stars,” Klement said. “Could they already have been able to form planets? That’s a very fascinating question.”
Vision of our solar system’s fate?
Our own sun is on the same stellar-evolution track as HIP 13044; scientists predict it will bloat into a red giant in 5 billion years or so. So astronomers may be able to learn something about the fate of our solar system by studying HIP 10344b and its parent star, researchers said.
That fate would not be pretty for Earth. HIP 13044b likely once orbited much farther away from its star but spiraled closer and closer during the red giant phase due to friction with the swollen star’s envelope, researchers said. Any more interior planets would have been destroyed during this process.
When our own sun enters its red giant phase, Earth will likely get cooked.
“The inner planets, including Earth, maybe will not survive,” Setiawan told SPACE.com. “But Jupiter, Saturn and the outer planets might move to closer-in orbits, exactly like we detected.”
HIP 13044b is a survivor, but it won’t live forever. Its parent star is due to expand again in the next phase of its stellar evolution, researchers said, and this time the planet will almost certainly be engulfed.
Will we find evidence of a real-life E.T. in the very near future?
A NASA press release announcing “an astrobiology finding” — something that will impact the search for extraterrestrial life — has sent shockwaves through the blogosphere.
The press release simply announces an event, set for Thursday at 2 p.m. EST, to discuss an astrobiology discovery “that will impact the search for evidence of extraterrestrial life.” Astrobiology is the study of the origin, evolution, distribution and future of life in the universe.
And the concept of NASA discussing alien life has everyone a-Twitter. Gawker, PC World, New Scientist and others have all speculated about the news — even suggesting that the space agency may reveal that E.T. has finally arrived.
The reality may be less dramatic, though still intriguing: Based on the background of the four conference participants NASA cites, the announcement will probably concern lifeforms that live off of poisonous arsenic. Popular blogger Jason Kottke and others have concluded that the announcement will tie into the quest for life on the Martian moon Titan.
“I’d say that they’ve discovered arsenic on Titan and maybe even detected chemical evidence of bacteria utilizing it for photosynthesis,” Kottke theorizes, a hypothesis short of actually confirming alien life.
He notes that geobiologist Pamela Conrad was the primary author of a 2009 paper on geology and life on Mars, while oceanographer Felisa Wolfe-Simon has written extensively on photosynthesis using arsenic. Biologist Steven Benner is on the “Titan Team” at NASA’s Jet Propulsion Laboratory; they’re looking at Saturn’s largest moon as an early-Earth-like chemical environment. And ecologist James Elser is involved with a NASA-funded astrobiology program called Follow the Elements, which studies the chemistry of environments where life evolves, not just water, carbon or oxygen.
Despite the hype and rumors, Phil Plait of Discover Magazine urged rational calm, noting that an announcement of the discovery of extraterrestrial life “seems really unlikely.” Plait called overreactions par for the course, citing a June press release about the lack of acetlyne in Titan’s atmosphere “that sparked vast speculation.”
“Even though the press release was clear enough, it was misleadingly reported as NASA finding sings of life on Titan,” Plait wrote.
Forbes blogger Brian Caulfield agreed, noting that “Thursday’s news is probably a big deal” but “probably just not that big a deal.”
Of course, there is always the chance that NASA has discovered alien life — right? We’ll know for sure tomorrow.
WASHINGTON, March 6 (Reuters) - A NASA scientist reports detecting tiny fossilized bacteria on three meteorites, and maintains these microscopic life forms are not native to Earth.
If confirmed, this research would suggest life in the universe is widespread and life on Earth may have come from elsewhere in the solar system, riding to our planet on space rocks like comets, moons and other astral bodies.
The study, published online late Friday in The Journal of Cosmology, is considered so controversial it is accompanied by a statement from the journal’s editor seeking other scientific comment, which is to be published starting on Monday.
The central claim of the study by astrobiologist Richard Hoover is that there is evidence of microfossils similar to cyanobacteria — blue-green algae, also known as pond scum — on the freshly fractured inner surfaces of three meteorites.
These microscopic structures had lots of carbon, a marker for Earth-type life, and almost no nitrogen, Hoover said in a telephone interview on Sunday.
Nitrogen can also be a sign of Earthly life, but the lack of it only means that whatever nitrogen was in these structures has decomposed out into a gaseous form long ago, Hoover said.
“We have known for a long time that there were very interesting biomarkers in carbonaceous meteorites and the detection of structures that are very similar ... to known terrestrial cyanobacteria is interesting in that it indicates that life is not restricted to the planet Earth,” Hoover said.
Hoover, based at NASA’s Marshall Space Flight Center in Alabama, has specialized in the study of microscopic lifeforms that survive extreme environments such as glaciers, permafrost and geysers.
He is not the first to claim discovery of microscopic life from other worlds.
In 1996, NASA scientists presented research indicating a 4-billion-year-old meteorite found in Antarctica carried evidence of fossilized microbial life from Mars.
The initial discovery of the so-called Mars meteorite was greeted with acclaim and the rock unveiled at a standing room-only briefing at NASA headquarters in Washington.
Since then, however, criticism has surrounded that discovery and conclusive proof has been elusive.
Hoover’s research may well meet the same fate. In a statement published with the online paper, the Journal of Cosmology’s editor in chief, Rudy Schild, said in a statement:
“Dr. Richard Hoover is a highly respected scientist and astrobiologist with a prestigious record of accomplishment at NASA. Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5,000 scientists from the scientific community to review the paper and to offer their critical analysis.”