NASA announced the discovery of a planet that is well positioned to support life. The planet is about 2.4 times the radius of Earth, orbits around a star similar to our sun and is located 600 light-years away. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets. The planet's host star belongs to the same class as our sun, called G-type, although it is slightly smaller and cooler.
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. And it has a shopping mall-like surface temperature of near 72 degrees, scientists say. “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 email. “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 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,” Batalha said in a phone interview. Kepler can’t find life itself, just where the conditions might be right for it to thrive. And when astronomers look for life elsewhere they’re talking about everything ranging from microbes to advanced intelligence that can be looking back at us. 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.
Source: NASA and Washington Post
