First Mars was the setting of imaginary declining civilizations; then it was a dead, cratered, Moon-like world. Thanks to a coordinated Mars exploration program that began in 1996 and continues to the present day, we now know Mars better than any world other than our own, yet we have more questions than ever.
Geologically, Mars is quiescent, but its atmosphere breathes and changes from year to year, interacting in complex ways with the water sequestered in Mars' ice caps and permafrost. Water does not, today, flow on Mars, but it evidently has in the past, and it may flow again in the future when Mars' rotation axis tilts much more steeply. Did Mars ever look like Earth, or has it always been as cold and dry as an Antarctic desert? Has there ever been the right combination of liquid water, available energy, and time to permit life to begin on Mars?
Latest Blogs from Mars
Curiosity is inching her way through her first use of the drill on a Martian rock. She paused in the proceedings to capture a second Martian "selfie."
Shooting video of a lumpy moon crossing the Sun and turning it into a giant googly eye is not a new activity for Curiosity, but I get a fresh thrill each time I see one of these sequences downlinked from the rover.
In 2016, The Planetary Society’s LightSail program will take the technology a step further.