Planet confirmed by NASA is best hope yet of a new Earth
Source: Agencies |
December 7, 2011, Wednesday
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A NEWLY discovered planet is eerily similar to Earth and is located in what seems to be the ideal place for life, except for one hitch. It is a bit too big.
The planet is smack in the middle of what astronomers call the Goldilocks zone, that hard to find place that is not too hot, not too cold, where water, which is essential for life, does not freeze or boil. And it has a shopping mall-like surface temperature of near 72 degrees, scientists say.
However, astronauts will not be visiting any time soon. The planet is 600 light years away - each light year is 9.5 trillion kilometers. It would take a space shuttle 22 million years to get there.
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.
This is the first planet confirmed in the habitable zone for Kepler, which already had found Earth-like rocky planets elsewhere. Twice before astronomers have announced a planet found in that zone, but neither has 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 Earth's solar system, said. "This discovery shows that we Homo sapiens are straining our reach into the universe to find planets that remind us of home. We are almost there."
The new planet, named Kepler-22b, has key aspects it shares with Earth. It circles a star that could be the twin of Earth's sun and at just about the same distance. The planet's year of 290 days is even close to Earth's. It probably has water and rock.
The trouble is, at about 2.4 times the size of Earth, the planet's a bit big for life to exist on the surface. It could be more like gas-and-liquid Neptune with 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," Batalha said.
Kepler cannot find life itself, just where the conditions might be right for it to thrive. And when astronomers look for life elsewhere, they are talking about everything ranging from microbes to advanced intelligence that can be looking back at us.
So far the Kepler telescope has spotted 2,326 candidate planets outside Earth's solar system with 139 of them potentially habitable ones. Even though the confirmed Kepler-22b is a bit big, it is smaller than most of the other candidates. It is closest to Earth in size, temperature and star than either of the two previously announced planets in the zone.
But for Marcy, who is on the Kepler team, the newest planet is a smidgen too large. "That smidgen makes all the difference," he said.
Because its size implies it is closer to Neptune in composition, "I would bet my telescope there is no hard, rocky surface to walk on," Marcy said.
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. It is in a size range that scientists do not really know anything about. Measurements next summer may help astronomers have a better idea of its makeup, he said.
"It's a great gift," Borucki said. "We consider this our Christmas planet."
The planet is smack in the middle of what astronomers call the Goldilocks zone, that hard to find place that is not too hot, not too cold, where water, which is essential for life, does not freeze or boil. And it has a shopping mall-like surface temperature of near 72 degrees, scientists say.
However, astronauts will not be visiting any time soon. The planet is 600 light years away - each light year is 9.5 trillion kilometers. It would take a space shuttle 22 million years to get there.
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.
This is the first planet confirmed in the habitable zone for Kepler, which already had found Earth-like rocky planets elsewhere. Twice before astronomers have announced a planet found in that zone, but neither has 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 Earth's solar system, said. "This discovery shows that we Homo sapiens are straining our reach into the universe to find planets that remind us of home. We are almost there."
The new planet, named Kepler-22b, has key aspects it shares with Earth. It circles a star that could be the twin of Earth's sun and at just about the same distance. The planet's year of 290 days is even close to Earth's. It probably has water and rock.
The trouble is, at about 2.4 times the size of Earth, the planet's a bit big for life to exist on the surface. It could be more like gas-and-liquid Neptune with 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," Batalha said.
Kepler cannot find life itself, just where the conditions might be right for it to thrive. And when astronomers look for life elsewhere, they are talking about everything ranging from microbes to advanced intelligence that can be looking back at us.
So far the Kepler telescope has spotted 2,326 candidate planets outside Earth's solar system with 139 of them potentially habitable ones. Even though the confirmed Kepler-22b is a bit big, it is smaller than most of the other candidates. It is closest to Earth in size, temperature and star than either of the two previously announced planets in the zone.
But for Marcy, who is on the Kepler team, the newest planet is a smidgen too large. "That smidgen makes all the difference," he said.
Because its size implies it is closer to Neptune in composition, "I would bet my telescope there is no hard, rocky surface to walk on," Marcy said.
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. It is in a size range that scientists do not really know anything about. Measurements next summer may help astronomers have a better idea of its makeup, he said.
"It's a great gift," Borucki said. "We consider this our Christmas planet."
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