There are few more potent reminders that Mars used to be a wet world than seeing ancient, dried up river beds etched into the red planet's surface.
In a decidedly wintry-looking scene, frost-filled fractures fills a crater near the north pole of Mars -- as observed by NASA's Mars Reconnaissance Orbiter.
Find out the results of this year's readers' choice poll for favorite space story of the year! Can you guess #1?
What's that? Not one, but a SWARM of dust devils on Mars!
Could the seismic fingerprint of dust devils detected on Earth be used to decipher the tiny tornadoes racing across the Martian surface?
By combining high-resolution observations of Mars dune ripples and comparing them with sand dunes on Earth, scientists are beginning to understand how surface winds influence the Red Planet.
Check out where 'The Martian's' Mark Watney was moving around in the fictional tale, using real photographs of Mars.
It might kill us, but the perchlorate-rich liquid water of Mars could be our best opportunity yet of rooting out the possibility of microbial Martian life.
+ Load More