NASA’s Curiosity Rover discovered areas with rocks enriched with mineral salts that are evidence of shallow ponds that used to be on the surface of the planet. Materials found by Curiosity show that Mars used to be covered in streams that went through cycles of overflowing then drying up. Using this new information, scientists want to know why Mars transitioned from a wet oasis to a freezing desert. Right now, Curiosity is exploring a “sulfate-bearing unit” which is an area that was most likely formed in an extremely dry environment. This area, along with another called Gale Crater, may have the clues needed to understand climate evolution on Mars.