The return of samples is a key objective of the Mars 2020 mission. The departure of the Perseverance rover to the red planet will begin an unprecedented adventure: never have samples been brought back from space in order to study the traces of the life.
The departure time is approaching for Perseverance. The NASA rover will have the mission, once it arrives on Mars, to collect samples on the surface of the star. The challenge will then be to bring them back to Earth, in the hope of learning more about possible traces of ancient life on the red planet. Organizing such a return of samples, with the prospect of analyzing them on Earth, is unprecedented in history.
« No space agency has ever brought back samples with the aim of studying the traces of life. Until now, all the samples that were brought back to Earth were with the aim of studying the chemical evolution of the Universe. For the first time, there is a microbiological dimension », Explains Adrienne Kish to Numerama, head of the bacteriology department at the National Museum of Natural History, specializing in exobiology.
The prospect of working on samples recovered in space is particularly unprecedented for the European Space Agency. ” The idea of processing samples brought back from space is a fairly new topic for Europe, continues Adrienne Kish. Until now, the samples that were analyzed were in situ [ndlr : là où ils étaient récoltés]. NASA and Jaxa have already brought back samples from the Moon (Apollo) or comets, asteroids (Hayabusa). With the return of Martian samples, for the first time Europe will enter this field, in collaboration with NASA in particular. »
A work started long before Perseverance
The ambition to study Martian samples on Earth from a microbiological perspective can only be considered because previous steps have been taken. ” We first tried to find out if there was water on Mars, then if there was organic matter, which we checked », Summarizes the scientist. It’s in mars 2014 that the Rover Curiosity found elements that NASA said supported the hypothesis of the presence of water on Mars. Since then, Curiosity has also discovered traces of a salt lake filling Gale crater. The rover also repeatedly detected organic matter on the surface of Mars.
« The question now is whether there was life at some point on Mars and if these microorganisms left traces, which are called biosignatures. »Adds Adrienne Kish. As such, the crater that the Perseverance rover will explore has been deemed even more promising than expected by scientists, because it could harbor carbonates and silica.
To finally solve the enigma of a potential life spent on Mars, rovers are very useful, but show their limits – all their instruments must be miniaturized. Hence the need to now consider this return of samples for microbiological analyzes. ” There are analyzes that can be done in situ with rovers. But we are limited with a rover: we can do a lot more analyzes with the samples in our hands and in research laboratories on Earth. », Summarizes Adrienne Kish.
