By NICOLX (Nicolas Le Maux)
Mars 2020 is a space mission which consists of deploying the Perseverance rover on Martian soil to study its surface and collect soil samples. This Mars exploration mission is being developed by JPL (NASA). It constitutes the first in a series of three missions whose final objective is to bring these samples back to Earth to allow their analysis.
As previous NASA Mars missions confirmed that liquid water flowed on the planet’s surface in the past, scientists deduced that living organisms may have developed at that time. The Perseverance rover must search for areas that may have preserved clues of this past life. The return of these samples to Earth, a complex, risky and expensive undertaking, is considered a priority project by the scientific community.
By digging and then analyzing the rocks of Mars, Perserverance rover has detected organic molecules into ten samples. They come from Jezero crater, within rock formations known as Maàz and Seitah, dated 2.3 to 2.6 billion years ago.
That’s a very important news ! It’s the subject of a new paper in the famous review “Nature”, published last July (the 12), and named : « Diverse organic-mineral associations in Jezero crater, Mars ».
About findings : the organic molecules and consequences
Organic molecules are composed of carbon, with other elements such as hydrogen, oxygen, nitrogen, and many others like phosphorus or sulfur.
These molecules are analyzed using an instrument: the « Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals ». It’s his extended name. But the short name is SHERLOC. In practice, SHERLOC has an ultraviolet light laser that makes organic particles shine. SHERLOCK can detected and located them When they glow. Then we can make a map. We can also make a cartography of these elements on the samples’ rocks.
Organic molecules constitute the « building blocks » of life, also called « bricks of life ». It’s not the first time organic molecules was found on Mars. The NASA’s rover Curiosity have found them before. But the facts are really différents now. Fluorescence detections show a wide variety of molecules’ classes. This Organic signals of different types suggest 3 points :
– First of all, rocks were probably in contact with liquid water environment ;
– In second, there may be present for a very long time ;
– Then, they would relate to different training mechanisms or process.
So, the real question is, what you all want to know : organic molecules found on samples rocks on the surface of Mars mean there was life ? Absolutly not. At this point, we really don’t know. There isn’t no proof of life yet, no evidence yet.First we had to answer : the samples come from Mars or exogenous sources ? We cannot exclude an origin from meteoritic infall or from interstellar dust… Then, we need to do further analysis on the samples. To make that, we must bring them back to the earth. It is the purpose of the Mars Sample return Mission that aim to bring back them into the next year.