How long will extraterrestrials have to keep twiddling their thumbs (or equivalent alien digits) waiting for humanity to call? According to NASA chief scientist Ellen Stofan, probably not long. At a panel discussion on habitable worlds and alien life on Tuesday, Stofan said she expected researchers to find real clues to extraterrestrial life—probably not intelligent life, but more likely alien microbes—within 10 years.
“I think we’re going to have strong indications of life beyond Earth within a decade and I think we’re going to have definitive evidence within 20-30 years. We know where to look, we know how to look, and in most cases we have the technology,” said Stofan who will be joining us in New York for World Science Festival 2015.
Stofan’s estimate for finding life within the next decade or two isn’t too far from the ones given by scientists Jack Szostak, Paul Davies, Sara Seager, and Dimitar Sasselov in the 2014 World Science Festival program “Alien Life: Will We Know It When We See It?”
What Makes Experts Think Alien Life Likely?
Why all the optimism? For starters, there’s water out there, and life on Earth evolved in the oceans. As Stofan said on Tuesday: “The water molecule has these really unique properties, we think. It’s a solvent. It moves things around. It has really unique properties that we think are really critical to the formation of life not just on here on Earth but on other bodies in the solar system.”
Also, there seem to be an abundance of planets out there in the galaxy: In one tiny fraction of space, the Kepler space telescope alone has found more than 4,600 exoplanet candidates, with 1,022 confirmed. Based on some of the systems found by Kepler, some scientists estimate there are 100 billion alien planets in the Milky Way galaxy, with maybe 17 billion of those being Earth-sized. And we’re starting to find complex organic molecules in other star systems, suggesting that it’s not a feature unique to our solar system. That adds up to a lot of potential targets to look at. And after all, as the writer Thomas Carlyle said (and Carl Sagan was fond of quoting), if all those planets are devoid of life, “what a waste of space.”