There are a lot of rocks on Mars, and most of them wouldn’t raise an eyebrow. But one in particular has revealed new insights about the ancient Martian atmosphere.
In 2013, Mars rover Curiosity identified large amounts of the element manganese in a piece of rock – which, by all accounts, shouldn’t have been there. Now, analysts say the discovery could be proof of a once-oxygenated Martian atmosphere.
Most planetary crusts are composed of basalt, a type of rock that forms when lava is cooled near a planet’s surface. Mars is no exception, so researchers expected that Curiosity would find plenty of basalt on the red planet. But on the formation dubbed “Caribou,” the rover found something unusual: manganese.
This element can be found in basalt, but only in trace amounts. The manganese would have to be concentrated significantly to reach the levels found on Caribou. Researchers say that condensed manganese could only form on Mars if, somehow, basalt rock was dissolved in oxygenated water.