NASA’s Curiosity Rover has just un’mars’ed evidence that the planet’s atmosphere once had a large percentage of water and was more Earth-like than previously imagined. Curiosity’s ChemCam observed high levels of manganese oxides in the rocks and found mineral-filled cracks in sandstones in the Gale crater near Kimberley (Mars, not Australia). This suggests that there were once high levels of free-floating oxygen and lakes of liquid water. On Earth, the kind of manganese that’s found on Mars would only be made involving atmospheric O2 or… wait for it… microbes! The scientists believe that after the planet’s magnetic field collapsed, the oxygen evaporated into the atmosphere and then out into space. Without the magnetic field, the surface was unprotected from ionising radiation which split water molecules into O2 and H2 atoms. The H2 escaped, but some of the O2 remained and oxidised the rocks creating the red dusty sheet over the surface.
About Curiosity Rover:
Curiosity is a car-sized robotic rover exploring Gale Crater on Mars as part of NASA’s Mars Science Laboratory mission (MSL). As of February 15, 2016, Curiosity has been on Mars for 1254 sols (1288 total days) since landing on August 6, 2012.