Martian Batteries

For years, astronomers have wondered where the Red Planet got its organic carbon compounds, which are associated with life as we know it on Earth. Organic carbon often comes from biological sources on Earth, but researchers have been working to figure out how they’re created on Mars. Now, a new analysis of martian meteorites indicates that the organic carbon on Mars may come from naturally-occurring “batteries.”By analyzing three meteorites that fell to Earth from Mars, a research team led by Andrew Steele of the Carnegie Institution for Science found that the meteorites hold organic carbon similar to the kind detected on Mars by NASA’s Curiosity rover. That allowed Steele and his team to study and reveal how organic carbon compounds are synthesized on Mars.The team found that the compounds were likely created by the electrochemical corrosion of martian minerals by salty liquid brine. This process works like a natural, corrosion-powered “battery,” providing energy for the reactions that create the compounds, Steele said in a press release This work stems from research in 2012, where Steele and his team confirmed that the organic carbon in these meteorites really did come from Mars and not any Earthly contamination. They also found that the carbon didn’t come from a biological source. This new work aimed to figure out where the carbon came from, if it wasn’t created by life.“Revealing the processes by which organic carbon compounds form on Mars has been a matter of tremendous interest for understanding its potential for habitability,” Steele said.“The reactions that are taking place are probably very similar to what happened on early Earth,” he adds. In fact, anywhere igneous rock is surrounded by salty brines, like in Europa's and Enceladus’ subsurface oceans, this process could occur.