Sorry, Methane And ‘Organics’ On Mars Are Not Evidence For Life
“In 2020, two next-generation rovers will launch: ESA’s ExoMars and NASA’s Mars 2020. Instead of indirect inferences and possibilities, we’ll actually be able to understand whether the origin of these molecules is geological or biological in nature. It’s important to keep an open mind and let science, rather than our hopes or fears, decide the answer. The evidence is building, and we’re finally gaining a more robust picture of how, exactly, Mars works.
It’s producing methane seasonally, contains loads of carbon-based compounds, and had a very watery past. But does that all add up to life, past or present? In 2018, the evidence doesn’t say “yes” just yet. But in just a few years, we just might have the answer. In a few years, for the first time, we might finally know if there’s life beyond Earth.”
We use the word “organics” a lot when we talk about life (and molecules) beyond Earth. But while that word may conjure up images of reproducing molecules, new cells, and life, the scientific definition is far more mundane: a molecule containing carbon. That means carbon monoxide and cyanide are organic, even though they may be toxic to life itself. The discovery of seasonally-varying methane on Mars is interesting, but it may be better evidence for something geologically compelling than it is for anything biological. Regardless of how you interpret it, one thing is for certain: everything we’ve found on Mars so far is not yet enough to claim evidence for life.