National Aeronautics and Space Administration

Is there life elsewhere?

Are we alone? This question is as old as humankind itself.  For millennia, people have turned their eyes to the stars and wondered if there are others like themselves out there. Does life, be it similar to our own or not, exist elsewhere in our Solar System? Our Galaxy?  Until some 15 years ago it was uncertain whether there were even any planets outside those in our own Solar System.  Today we know of literally hundreds of planets orbiting other stars.  Do any of these planets have conditions that would support life?  What conditions favor the formation of terrestrial-class planets in developing planetary systems?  NASA can help address these questions by developing missions designed to find and characterize extrasolar planetary systems.

Before we can determine if there are other planetary systems capable of supporting life, we must first find them.  NASA Science pursues this goal by supporting a focused suite of ground-based observations and through the development of the Kepler mission, a space-based observatory dedicated to identifying and determining the prevalence (how many there are per star) of extrasolar planets. NASA Science is also actively planning future space missions that will determine the masses, orbits, temperatures and atmospheric compositions of extrasolar planets with unprecedented accuracy. When we know these quantities we will be able to address the questions: