Where did we come from? Are we alone in the Universe? We can only answer these questions by exploring the planets and other worlds of our solar system and beyond. Learn why these worlds are so important, and how you can get involved.
Saturn's largest moon, Titan, is both the only other place in the solar system with liquid on its surface and the only moon with a thick atmosphere, making it a tantalizing destination to search for life.
What is a Planet?
It's right there in our name: The Planetary Society. But what is a planet? This seemingly simple question is the subject of much debate.Learn More
As Spirit slept soundly after another near-perfect day of picture taking, science gathering, and data relays from Mars, NASA released the first color 360-degree panorama postcard it sent home.
Spirit is up -- standing at full height on all six wheels -- and is ready to roll off the lander heading west by northwest, probably sometime early Thursday morning Earth time, according to the latest plan.
Spirit continues to return
If a Hollywood screenwriter had crafted the scenes for the last few days of the Spirit Mission Team at JPL as they really happened -- success after success, triumphant image after triumph he or she would be out of a job.