On November 26th, 2011, NASA launched their Curiosity rover to mars to explore the Gale Crater: a 100 mile wide ancient basin. In a paper published by Nature Geoscience, the authors discuss rocks enriched in mineral salts found by Curiosity. These rocks serve as evidence of briny ponds that went through episodes of overflowing and drying out over the millions of years Mars has existed. The salt deposits in the rocks serve as a watermark for the transition from a wetter Mars to the freezing desert we know today.
Gale Crater, the area being observed by Curiosity, formed after an ancient massive impact on the surface of mars. Sediment carried by water and wind slowly filled the crater and created a peak known as Mount Sharp. As Curiosity climbs the hill of Mount Sharp it observes the different layers of sediment built up on the slopes which hold clues to the environments of different periods of Martian history. Scientists have noticed a trend from a wet landscape to a drier one as Curiosity continues up the mountain.
“Understanding when and how the planet’s climate started evolving is a piece of another puzzle: When and how long was Mars capable of supporting microbial life at the surface?” Said lead author William Rapin of Caltech
With the proof of water once existing on the surface comes the possibility of Mars once harbouring life. With the new evidence being reported by Curiosity it’s obvious that Mars once contained water and has been experiencing a drying period ever since. What were once lakes possibly containing life are now barren craters. Did Mars once support life? Time will tell as Curiosity continues its mission across the red planet.