The proportion of planets capable of supporting life may be much higher than scientists previously thought, Shostak said.
“Personally, given the line of work I’m in, I think that’s a very encouraging thing,” Shostak said.
“Each one we find helps us to answer the question of what fraction of the sky has planets that are cousins of our own. That fraction is looking pretty promising. It’s not one in a million. It’s not one in a thousand … It may be more like one in two or one in five.”
The Seti (search for extraterrestrial intelligence) Institute, is a private nonprofit organization that aims to discover the origin and nature of life in the universe. They have been using the Allen Telescope Array – a group of 42 antennas north of San Francisco – to monitor various frequencies for radio signals and search for sophisticated life on Kepler 452b. Even though they haven’t found any signs of life thus far, they haven’t finished their search yet.
“At this point the inhabitants, if there are any, have remained coy,” Shostak said. “But there are many ways that you can miss a signal, of course. The fact that you don’t pick up a signal doesn’t mean that there isn’t anybody there.”
Because Kepler 452b is about 1,400 light years away, the Seti Institute is limited in the ways it can search for life. The Allen Telescope Array will only pick up on radio signal activity, so the lifeform would have to be advanced. The planet is too far away to see if it plays host to either bacteria or extremophiles, organisms that thrive in extreme environments.
John Grunsfeld, associate administrator for Nasa’s mission directorate, said Kepler 452b is “the closest twin to Earth, or the Earth 2.0 that we’ve found so far in the dataset”.
The 12 other possible habitable planets are also being searched by the Seti Institute. Shostak could not speak to their results for those planets thus far.