The ExoMars spacecraft is on its way to the red planet right now, and when it gets there it’s going to be looking for methane, a gas that’s linked to life, but could be coming from other sources too.
Point of view
"Looking for life is not trivial, and proving that it's there is very difficult"CaSSIS instrument project scientist, University of Bern
Nicolas Thomas, CaSSIS instrument project scientist, from University of Bern in Switzerland explains how his instrument on ExoMars could help solve the methane mystery.
ExoMars is a joint ESA-Roscosmos project, and includes the 2016 Trace Gas Orbiter and a small lander, and in 2020 the ExoMars rover, which will drill below the Martian surface to search for signs of life now or in the past.
“CaSSIS is designed to look at dynamic processes on the surface of Mars, and so we’ll be looking at things that are happening, changes that are occurring on the surface,” Thomas says.
So what could be producing methane on Mars, apart from life? “There are volcanic mechanisms that can produce methane, and that’s got very little to do with life in that particular case. We know that there are meteorite impacts on the surface of Mars. This exposes fresh material from under the surface, and that fresh material could be containing some trace gas material, like methane for example.”
“We also have evidence for avalanches. There might be gas trapped there, it’s then exposed, it gets into the atmosphere, and who knows, maybe it’s detectable with the ExoMars Trace Gas Orbiter’s instruments.”
His conclusion: “Production of methane is not necessarily to do with life, there are other processes that can produce methane. So, looking for life is not trivial, and proving that it’s there is very difficult.”