After five years on Mars, the Curiosity rover is an old pro at doing science on the Red Planet. Since sticking its landingon August 5, 2012, NASA’s Little Robot That Could has learned a lot about its environs.
Its charge was simple: Look for signs that Gale crater, a huge impact basin with a mountain at its center, might once have been habitable (for microbes, not Matt Damon). Turning over rocks across the crater, the rover has compiled evidence of ancient water — a lake fed by rivers once occupied the crater itself — and organic compounds and other chemicals essential for life.
NASA has extended the mission through October 2018. And there’s still plenty of interesting chemistry and geology to be done. As the robot continues to climb Mount Sharp at the center of the crater, Curiosity will explore three new rock layers: one dominated by the iron mineral hematite, one dominated by clay and one with lots of sulfate salts.
So, here are four Martian mysteries that Curiosity could solve (or at least dig up some dirt on).