NASA spots Earth’s twin (or closest match yet) outside solar system

Bill Borucki, Kepler principal Investigator at NASA's Ames Research Center, speaks during a news conference about the newly discovered planet Kepler-22b on Monday in in Moffett Field, Calif.

A newly discovered planet is eerily similar to Earth and is sitting outside our solar system in what seems to be the ideal place for life, expect for one hitch. It’s a bit too big.

The planet is smack in the middle of what astronomers call the Goldilocks zone, that hard-to-find place that’s not too hot, not too cold, where water, which is essential for life, doesn’t freeze or boil. Its surface temperature is near 22 C, scientists say.

The planet’s confirmation was announced Monday by NASA along with other discoveries by its Kepler telescope, which was launched on a planet-hunting mission in 2009.

That’s the first planet confirmed in the habitable zone for Kepler, which had already found Earth-like rocky planets elsewhere. Twice before astronomers have announced a planet found in that zone, but neither have been as promising.

“This is a phenomenal discovery in the course of human history,” Geoff Marcy of University of California, Berkeley, one of the pioneers of planet-hunting outside our solar system, said in an e-mail.

The new planet – named Kepler-22b – has key aspects it shares with Earth. It circles a star that could be the twin of our sun and at just about the same distance. The planet’s year of 290 days is even close to ours. It likely has water and rock.

The only trouble is the planet’s a bit big for life to exist on the surface. The planet is about 2.4 times the size of Earth. It could be more like the gas-and-liquid Neptune with only a rocky core and mostly ocean.

“It’s so exciting to imagine the possibilities,” said Natalie Batalha, the Kepler deputy science chief.

Floating on that “world completely covered in water” could be like being on an Earth ocean and “it’s not beyond the realm of possibility that life could exist in such an ocean,” Ms. Batalha said in a phone interview.

So far the Kepler telescope has spotted 2,326 candidate planets outside our solar system with 139 of them potentially habitable ones. Even though the confirmed Kepler-22b is a bit big, it is still smaller than most of the other candidates.

Chief Kepler scientist William Borucki said he thinks the planet is somewhere between Earth and gas-and-liquid Neptune, but that it has a lot of rocky material.

The planet is 600 light years away. Each light year is 5.9 trillion miles. It would take a space shuttle about 22 million years to get there.

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NASA finds 90 per cent of potential Earth-killer asteroids

If you’re worried about a killer asteroid wiping out Earth, NASA has some good news.

The U.S. space agency said Thursday it has identified more than 90 per cent of giant, potentially Earth-threatening asteroids, including ones as big as the one thought to have killed the dinosaurs eons ago.
“We know now where most of them are and where most of them are going. That really has reduced our risk” of an impact, said Amy Mainzer of the NASA Jet Propulsion Laboratory.

NASA researchers also downgraded their estimate of the number of medium-sized asteroids, saying there are 44 per cent fewer than previously believed. The downside is that scientists have yet to find many of these mid-sized asteroids, which could destroy a metropolitan city.

“Fewer does not mean none,” Ms. Mainzer said. “There are still tens of thousands out there that are left to find.”

The updated census comes from data from NASA’s sky-mapping spacecraft named Wide-field Infrared Survey Explorer, or WISE, which launched in 2009 to seek out near-Earth objects, galaxies, stars and other cosmic targets.

Unlike previous sky surveys, WISE has sensitive instruments that can pick out both dark and light objects, allowing it to get the most accurate count yet of near-Earth asteroids. The spacecraft takes a small sample of asteroids of varying sizes and then estimates how large the population would be.

For the largest asteroids – bigger than 1,000 metres across – NASA said 911 of the 981 thought to exist have been found. None poses a threat to Earth in the near future, the space agency said.

Previous estimates put the number of medium-sized asteroids at 35,000, but WISE data indicate there are about 19,500 between 100 and 1,000 metres wide. Only about 5,200 have been found and scientists said there is still a lot of work left to identify the potentially hazardous ones.

Results were published in the Astrophysical Journal.

WISE is not equipped to detect the more than one million smallest asteroids that could cause damage if they impact Earth. The spacecraft recently ran out of coolant and is currently in hibernation.

By locating most of the giant asteroids, NASA has fulfilled a goal set by Congress in 1998. More recently, the space agency has been asked to find 90 per cent of asteroids that are at least 140 metres in diameter by 2020.

Don Yeomans, who heads NASA’s Near-Earth Object Program Office, said that goal is about 35-per-cent complete.

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Falling NASA satellite to pass over Canada

A 6-ton NASA satellite on a collision course with Earth clung to space Friday, apparently flipping position in its ever-lower orbit and stalling its death plunge.

The old research spacecraft was targeted to crash through the atmosphere sometime Friday night or early Saturday, putting Canada and Africa in the potential crosshairs, although most of the satellite should burn up during re-entry. The United States wasn't entirely out of the woods; the possible strike zone skirted Washington state.

“It just doesn't want to come down,” said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics.

McDowell said the satellite's delayed demise demonstrates how unreliable predictions can be. That said, “the best guess is that it will still splash in the ocean, just because there's more ocean out there.”

Until Friday, increased solar activity was causing the atmosphere to expand and the 35-foot, bus-size satellite to free fall more quickly. But late Friday morning, NASA said the sun was no longer the major factor in the rate of descent and that the satellite's position, shape or both had changed by the time it slipped down to a 100-mile orbit.

“In the last 24 hours, something has happened to the spacecraft,” said NASA orbital debris scientist Mark Matney.

On Friday night, NASA said it expected the satellite to come crashing down between 11:45 p.m. and 12:45 a.m. EDT Saturday. It was going to be passing over the Atlantic, Pacific and Indian oceans at that time, as well as Canada and Africa.

“The risk to public safety is very remote,” NASA said in a statement.

Any surviving wreckage is expected to be limited to a 500-mile swath.

The Upper Atmosphere Research Satellite, or UARS, will be the biggest NASA spacecraft to crash back to Earth, uncontrolled, since the post-Apollo 75-ton Skylab space station and the more than 10-ton Pegasus 2 satellite, both in 1979.

Russia's 135-ton Mir space station slammed through the atmosphere in 2001, but it was a controlled dive into the Pacific.

Some 26 pieces of the UARS satellite — representing 1,200 pounds of heavy metal — are expected to rain down somewhere. The biggest surviving chunk should be no more than 300 pounds.

Earthlings can take comfort in the fact that no one has ever been hurt by falling space junk — to anyone's knowledge — and there has been no serious property damage. NASA put the chances that somebody somewhere on Earth would get hurt at 1-in-3,200. But any one person's odds of being struck were estimated at 1-in-22 trillion, given there are 7 billion people on the planet.

“Keep in mind that we have bits of debris re-entering the atmosphere every single day,” Matney said in brief remarks broadcast on NASA TV.

In any case, finders definitely aren't keepers.

Any surviving wreckage belongs to NASA, and it is against the law to keep or sell even the smallest piece. There are no toxic chemicals on board, but sharp edges could be dangerous, so the space agency is warning the public to keep hands off and call police.

The $740 million UARS was launched in 1991 from space shuttle Discovery to study the atmosphere and the ozone layer. At the time, the rules weren't as firm for safe satellite disposal; now a spacecraft must be built to burn up upon re-entry or have a motor to propel it into a much higher, long-term orbit.

NASA shut UARS down in 2005 after lowering its orbit to hurry its end. A potential satellite-retrieval mission was ruled out following the 2003 shuttle Columbia disaster, and NASA did not want the satellite hanging around orbit posing a debris hazard.

Space junk is a growing problem in low-Earth orbit. More than 20,000 pieces of debris, at least 4 inches in diameter, are being tracked on a daily basis. These objects pose a serious threat to the International Space Station.

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NASA launches spacecraft on five-year trip to Jupiter

A sun-powered robotic explorer named Juno rocketed away Friday on a five-year journey to Jupiter, the solar system's most massive and ancient planet.

Hundreds of scientists and their families and friends watched from just a few miles away, cheering and yelling, “Go Juno!” as the NASA spacecraft soared into a clear midday sky atop an unmanned rocket.

“It's fantastic!” said Fran Bagenal, a planetary scientist at the University of Colorado at Boulder, who is part of the project. “Just great to see the thing lift off.”

It was the first step in Juno's 1.7 billion-mile voyage to the gas giant Jupiter, just two planets away but altogether different from Earth and next-door neighbour Mars.

Juno is solar powered, a first for a spacecraft meant to roam so far from the sun. It has three huge solar panels that were folded for launch. Once opened, they should each stretch as long and wide as a tractor-trailer. Previous spacecraft to the outer planets have relied on nuclear energy.

With Juno, scientists hope to answer some of the most fundamental questions of our solar system.

“How Jupiter formed. How it evolved. What really happened early in the solar system that eventually led to all of us,” said Juno's chief investigator Scott Bolton, an astrophysicist at Southwest Research Institute in San Antonio.

Mr. Bolton said Jupiter is like a time capsule. It got most of the leftovers from the sun's creation nearly 5 billion years ago — hence the planet's immense size — and its enormous gravity field has enabled it to hold onto that original material.

Jupiter is so big it could hold everything in the solar system, minus the sun, and still be twice as massive. Astronomers say it probably was the first planet in the solar system to form.

Juno will venture much closer to Jupiter than any of the eight spacecraft that have visited Jupiter since the 1970s. Juno represents the next step, Mr. Bolton said.

“We look deeper. We go much closer. We're going over the poles. So we're doing a lot of new things that have never been done, and we're going to get all this brand-new information,” Mr. Bolton said.

The $1.1 billion mission — which will end with Juno taking a fatal plunge into Jupiter in 2017 — kicks off a flurry of astronomy missions by NASA.

Juno's liftoff appeared to create more buzz than usual, given the hiatus in human launches from the United States — the space shuttle program ended two weeks ago. NASA's long-term goal is to send astronauts to an asteroid by 2025 and to Mars in the mid-2030s.

There are a few special passengers aboard Juno, though.

Attached to the probe are three little Lego figures specially made of space-grade aluminum. They represent the Italian physicist Galileo, who discovered Jupiter's four biggest moons; the Roman god Jupiter; and his wife Juno, for whom the spacecraft is named.

If all goes well, Juno will go into orbit around Jupiter's poles — a first — on July 4, 2016.

The oblong orbit will bring Juno within 3,100 miles of the cloudtops and right over the most powerful auroras in the solar system. In fact, that's how the spacecraft got its name — Juno peered through clouds to keep tabs on her husband, Jupiter.

Juno will circle the planet 33 times, each orbit lasting 11 days for a grand total of one year.

With each orbit, the spacecraft will pass over a different longitude so that by mission's end, “we've essentially dropped a net around the planet with all of our measurements,” Bolton said. That's crucial for understanding Jupiter's invisible gravity and magnetic force fields, he noted.

Radiation is so intense around Jupiter that Bolton and his team put Juno's most sensitive electronics inside a titanium vault — an armoured tank, as he calls it.

Juno's experiments also will attempt to ascertain the abundance of water, and oxygen, in Jupiter's atmosphere, and determine whether the core of the planet is solid or gaseous.

After Juno, next up is Grail, twin spacecraft that will be launched next month and go into orbit around Earth's moon. Then comes Curiosity, a six-wheeled, jeep-size rover that will blast off for Mars at the end of November in search of environments conducive to life.

All the upcoming astronomy probes show “we still continue an exciting group of missions,” said Colleen Hartman of NASA's science mission office. Robotic missions “have a role to play in how humans explore the universe, and so it's important that, in fact, both these sides of the house do well.”

Juno bears nine instruments, including a wide-angle colour camera, JunoCam, that will beam back images that the public can turn into photos.

The spacecraft also bears a small Italian-supplied plaque honouring Galileo. It shows his self-portrait, as well as his description of observing Jupiter's moons, in his own handwriting from 1610.

Unlike many other NASA missions, this one came in on cost and on time. It's relatively inexpensive; the Cassini probe launched in 1997 to Saturn, by way of Jupiter, cost $3.4 billion.

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NASA launches twin satellites to study insides of moon

A pair of spacecraft rocketed toward the moon Saturday on the first mission dedicated to measuring lunar gravity and determining what’s inside Earth’s orbiting companion – all the way down to the core.

“I could hardly be happier,” said the lead scientist, Maria Zuber. After two days of delays and almost another, “I was trying to be as calm as I could be.”

NASA launched the near identical probes – named Grail-A and Grail-B – aboard a relatively small Delta II rocket to save money. It will take close to four months for the spacecraft to reach the moon, a long, roundabout journey compared with the zippy three-day trip of the Apollo astronauts four decades ago.

Grail-A popped off the upper stage of the rocket exactly as planned 1 1 / 2 hours after liftoff, followed eight minutes later by Grail-B. Both releases were seen live on NASA TV thanks to an on-board rocket camera, and generated loud applause in Launch Control.

The spacecraft are travelling independently to the moon, with A arriving on New Year’s Eve and B on New Year’s Day.

Once they were safely on their way, Ms. Zuber announced a contest for schoolchildren to replace the “working-class names” of Grail-A and Grail-B.

“Grail, simply put, is a journey to the centre of the moon,” said Ed Weiler, head of NASA’s science mission directorate, borrowing from the title of the Jules Verne science fiction classic, “Journey to the Centre of the Earth.”

The world has launched more than 100 missions to the moon since the Soviet Union’s Luna probes in 1959. That includes NASA’s six Apollo moon landings that put 12 men on the lunar surface.

NASA’s Grail twins – each the size of a washing machine – won’t land on the moon but will conduct their science survey from a polar lunar orbit.

Beginning in March, once the spacecraft are orbiting just 34 miles above the moon’s surface, scientists will monitor the slight variations in distance between the two to map the moon’s entire gravitational field. The measurements will continue through May.

“It will probe the interior of the moon and map its gravity field 100 to 1,000 times better than ever before. We will learn more about the interior of the moon with Grail than all previous lunar missions combined,” Mr. Weiler said.

At the same time, four cameras on each spacecraft will offer schoolchildren the opportunity to order up whatever pictures of the moon they want. The educational effort, called MoonKAM, is spearheaded by Sally Ride, America’s first spacewoman. As of Saturday, more than 1,100 schools had signed up.

The entire Grail mission costs $496-million.

Ms. Zuber, the mission’s principal investigator and a planetary scientist at the Massachusetts Institute of Technology, said the precise lunar gravity measurements will help her and other planetary scientists better understand how the moon evolved over the past 4 billion years. The findings also should help identify the composition of the moon’s core: whether it’s made of solid iron or possibly titanium oxide.

Another puzzle that Grail may help solve, Ms. Zuber said, is whether Earth indeed had a smaller second moon. Last month, astronomers suggested the two moons collided and the little one glommed onto the big one, a possible explanation for how the lunar highlands came to be.

Knowing where the moon’s gravity is stronger will enable the United States and other countries to better pinpoint landing locations for future explorers, whether robot or human. The gravity on the moon is uneven and about one-sixth Earth’s pull.

“If you want to land right next to a particular outcrop (of rock), you’re going to be able to do it,” Ms. Zuber said. “There will be no reason to do another gravity experiment of the moon in any of our lifetimes.”

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Reports NASA satellite debris fell in Alberta may be misguided

NASA’s massive defunct satellite hit Earth Saturday, followed by rampant – and perhaps misguided – speculation that it crashed near a city in Alberta.

NASA does not know where the six-ton piece of space junk landed, but excited Twitter users are pushing for Okotoks, immediately south of Calgary.

But Dr. Phil Langill, director of the University of Calgary's Rothney Astrophysical Observatory 30 kilometres southwest of Calgary, said he hasn't heard anything about a debris field in the region.

His telescopes would have "no scientific reason to track" the falling satellite since it would only be "something cool to see in the sky."

He doubts anything would have fallen in this area.

"It would be a bit of a miracle," he said.

Twitter users are backing up their claims with a six and a half minute video circulating the Internet. A glittery streak in the sky can be seen, and excited voices heard, on the video, seemingly shot with an iPhone. While the YouTube posting says the pictures are from Okotoks, the amateur videographer who was out for a walk is nowhere near the Canadian city.

“I’m [in] Oklahoma City, looking southeast,” he says on the video. “I just wish people could see this, because this is crazy.”

He states that the date is September 22. Two U.S. government agencies said the 35-foot satellite fell sometime between 11:23 p.m. EDT Friday, September 23, and 1:09 a.m. EDT Saturday, September 24, but with no precise time or location.

RCMP Sgt. Patrick Webb says the video is likely a hoax, adding police have heard nothing about falling debris in the area.

Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics says the spacecraft entered the atmosphere around 12:15 a.m. eastern time over the coast of Washington state.

He says much of the debris likely fell over the Pacific Ocean, with some making it to Canada over northern Alberta and perhaps as far as the Hudson Bay.

Mr. McDowell said he'd be surprised if anyone was hurt by the debris because it appears to have fallen in such remote areas.

“I do think people saw lights in the sky and fireballs and may well be bits of UARS falling down,” he said.

The bus-sized satellite first penetrated Earth's atmosphere somewhere over the Pacific Ocean, according to NASA and the U.S. Air Force's Joint Space Operations Center. But that doesn't necessarily mean it all fell into the sea.

NASA spokesman Steve Cole said that was possible Alberta was hit because the last track for the satellite included Canada, starting north of Seattle and then in a large arc north then south. From there, the track continued through the Atlantic south toward Africa, but it was unlikely the satellite got that far if it started falling over the Pacific.

Mr. Cole said NASA was hoping for more details from the Air Force, which was responsible for tracking debris.

NASA's earlier calculations had predicted that the 20-year-old former climate research satellite would fall over an 800-kilometre swath and could include land.

Because the plummet began over the ocean and given the lack of any reports of people being hit, that “gives us a good feeling that no one was hurt,” but officials didn't know for certain, Mr. Cole told The Associated Press.

Given where the satellite may have fallen, officials may never quite know precisely.

“Most space debris is in the ocean. It'll be hard to confirm,” Mr. Cole said.

Some 26 pieces of the satellite representing 1,200 pounds of heavy metal had been expected to rain down somewhere. The biggest surviving chunk should be no more than 135 kilograms.

The Upper Atmosphere Research Satellite is the biggest NASA spacecraft to crash back to Earth, uncontrolled, since the post-Apollo 75-ton Skylab space station and the more than 10-ton Pegasus 2 satellite, both in 1979.

Russia's 135-ton Mir space station slammed through the atmosphere in 2001, but it was a controlled dive into the Pacific.

Before UARS fell, no one had ever been hit by falling space junk and NASA expected that not to change.

NASA put the chances that somebody somewhere on Earth would get hurt at 1-in-3,200. But any one person's odds of being struck were estimated at 1-in-22 trillion, given there are seven billion people on the planet.

The satellite ran out of fuel and died in 2005. UARS was built and launched before NASA and other nations started new programs that prevent this type of uncontrolled crashes of satellite.

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