Scientists have identified a rock that has the ability to preserve traces of life. Explanations.
It is called mirabilite: this rock found on Mars is composed of crystals that form in hypersaline water. If scientists are interested in it, it is because it is present both on Earth, in particular in the great salt lake of Utah in the United States, and therefore on Mars in more or less analogous forms, since knows that the red planet once had basins filled with salt water.
>> Space: the objective of living on Mars is becoming clearer
This rock is of particular interest to us, above all, because we now know – thanks to a team of American researchers – that it is capable of preserving biosignatures. Chemical indices which can attest, testify, of the appearance of a primitive life. And when we talk about primitive life, we are talking about bacterial life.
Extreme conditions
The study of this rock on Earth has proven that it could contain bacteria, algae, or other extremophilic microorganisms, that is to say bacteria that develop and resist in extreme conditions. , conditions lethal to most other organisms, such as hyper-high temperatures, up to 100°C or infinitely low, in radioactive or salt-saturated environments.
To give an example, in Australia last year, micro-organisms 830 million years old were found trapped in this mineral. It is moreover this discovery which made scientists think that there was a track to study with perhaps the beginning of a solution to these questions which had remained unanswered until then: how to know if Mars once housed the life and especially where to look?
Wait until 2030
We now have a target to explore and it is the Perseverance rover that will explore this track. The NASA robot, which landed on Mars last year, will be able to take these samples. He will collect the minerals, put them in tubes and his mission will stop there because he cannot, unfortunately, do the analyzes in situ. We will therefore have to wait for the return to earth of the Martian samples from 2030. But now that we know where to look. We can wait a bit to solve an enigma as important as life on Mars.