Studies made by Curiosity rover between 2012 and 2017 revealed thiophenes

A tireless worker: Curiosity, landed on Mars in 2012, is unstoppable. Its activity allows to discover something new everyday, week after week, year after year with one single purpose: find life elements on Mars! Yes, obviously, not human life as we know it, but rather a sort of biological traces.

A news of few days ago reported that Curiosity found thiophenes in some sediments of Mars ground. What are thiophenes? Thiophenes are molecular element of organic matter class, that even exist here on Earth: they are formed by 4 carbon-atoms, 1 sulfur-atom and 4 hydrogen-atoms linked with carbon atoms, and you can find, for examples, in carbon, petroleum and also in white truffles.

How are they formed?

Well, the two astrobiologists Jacob Heinzm (Technische Universitat di Berlino) and Dirk Schulze-Makuch (Washington State University) suggest that the presence of thiophenes would be possible by an organic process due to some bacteria. This is a possible scenario, which would indirectly confirm existence of life forms in the past of Mars. But...

...the presence of thiophenes could be possible due to meteors impact or even due to a process called thermochemical sulphate reduction that provides heating a set of compounds to temperatures over 120 degrees Celsius and producing the compound as a by-product of the reactions. But this last process could be possible even because of bacteria! It's called bacterial sulfate reduction.

Actually it's to early to know if this elements come form bacteria or chemical process: the next mission, EVA, would will explain more preciously this new discover