The Curiosity robot has detected organic matter, which means that there may have been life in the past …

Let’s get straight to the point: the discovery does not prove that there is, or has been, life on Mars. But this is an advance in the study of potential traces of life on the red planet.
 #BREAKING @NASA news! @MarsCuriosity rover found organic molecules on Mars! While this doesn’t mean that we’ve found concrete evidence of life on Mars, it is a good sign in our continuing search. We’re sending the Mars 2020 rover to dig deeper! https://t.co/sU0wYlkZSu

The Curiosity vehicle has detected the most complex organic matter ever found on the surface of Mars, NASA scientists said Thursday. Samples from 3.5-billion-year-old rocks were collected 5 cm deep at the base of Mount Sharp, inside the Gale crater, considered an ancient lake.

In search of a life signature

“This is a significant advance as it indicates that organic matter is being preserved in the harshest environments of Mars,” said lead author of one of two studies published in the journal Science , astrobiologist Jennifer Eigenbrode , from the Goddard Center of the US Space Agency. Samples of organic matter can come from a meteorite or geological formations equivalent to coal or black shale found on Earth, or a form of life, she said. “And maybe we can find something better preserved that contains a signature of life,” she told AFP.

Curiosity, which landed on the red planet in 2012, had already discovered organic matter in 2014, in small quantities. “This study shows in detail the discovery of complex and diverse organic compounds in sediments. This does not mean that there is life, but organic compounds are the building blocks of life, “said AFP co-author Sanjeev Gupta, professor of Earth science at the Imperial College London.

Fumes of methane that vary

The little robot has also discovered evidence of seasonal variations in methane emissions, indicating that the source of this gas – which is often a sign of biological activity – comes from the planet itself. Methane can have a geological, chemical or biological origin. Fumes range from 0.24 to 0.65 parts per billion by volume, with a peak at the end of summer in the northern hemisphere.

These discoveries tend to support the thesis that life has potentially existed on Mars, says Inge Loes ten Kate, from the University of Tübingen in Germany. “Curiosity has shown that the Gale Crater was habitable about 3.5 billion years ago, with conditions comparable to those of the Earth Formation, where life evolved at that time,” she added.