When will NASA discover alien life?

NASA Chief Scientist Ellen Stofan said in a recent panel discussion that because scientists know where to look for alien life and how to look for it, that alien life will be found within the next 30 years. Our galaxy is a “soggy place,” said Paul Hertz, director of NASA's Astrophysics Division.

“We can see water in the interstellar clouds from which planetary systems and stellar systems form,” he said. “We can see water in the disks of debris that are going to become planetary systems around other stars, and we can even see comets being dissipated in other solar systems as [their] star evaporates them."

Upcoming NASA projects include a mission to Europa, one of Jupiter’s moons, as early as 2022 and potentially the Wide-Field Infrared Survey Telescope project, which might launch in about 10 years.