Life on Mars? The discovery of an organic molecule opens up new perspectives
Curiosity in the Gale crater. © NASA/JPL
These are the largest organic molecules never found on Mars. Such a discovery shows that prebiotic chemistry, the one that leads to the living, has evolved at a high level on the red planet. We owe this magnificent find at the Rover Curiosity, present on March since 2012 and a sort of big brother of Perseverance. Curiosity is evolving in the Gale crater, where we know that water was present for very long periods, perhaps greater than millions of years.
What is this molecule and why is it a fantastic discovery?
The molecules found on Mars are surely fragments of fatty acids. © NASA / DAN GALLAGHER
These organic compounds, the decline, the Undecane and the Dodecane, each made up of 10, 11 and 12 carbon, seem to be fragments of fatty acids. They come from sprayed rock samples and analyzed in the Martian laboratory of Curiosity named SAM (Sample Analysis at Mars).
On earth, fatty acids are organic molecules among the chemical elements of life. Fumes secretly secretly secret from the Undecane as a warning signal. But there are also biological processes that can lead to the formation of these molecules without calling on the living, like certain hydrothermal events.
The analyzed sample was collected on May 19, 2013 on the planet Mars. © NASA/JPL-CALTECH/MSSS
A level of chemical complexity sufficient for the living?
In any case, this is an excellent news for those who feared that any sign of past life could have been erased from the red planet after billions of years. Oxidation and cosmic rays obviously did not destroy all of these complex molecules. It is also proof that organic chemistry has reached a very high level of complexity on Mars, perhaps sufficient for life to have existed at the time when the fourth planet of the solar system was not as arid as it is today …
The main author of this study which makes great noise is French, it is Caroline Fressinet, researcher at the CNRS. “Our study proves that, even today, by analyzing samples of March, we could detect the chemical signatures of past life, if it has never existed on Mars”she said.
Caroline Fressinet had already co -edited a team in 2015 which had shown the presence of organic molecules in the same sample. “We are ready to take the next big step and bring Martian samples to our laboratories to settle the debate about life on Mars”also assures Daniel Glavin, scientist at the Goddard Space Flight Center and co -author of the study.
