HOUSTON -- Is there life on other planets? NASA's chief scientist thinks so.
Ellen Stofan told a live webcast Tuesday that she expects to see strong indications of life beyond earth within a decade.
She says definitive evidence will also appear in 20 to 30 years.
Stofan says much of the technology already exists to look for alien life and NASA is on the path to implement it.
NASA is hoping to launch the next mars rover and a mission to one of Jupiter's moons within a decade.