“We have traveled a little more than 28 km in ten years”, explains a scientist

“We have covered a little more than 28 km in ten years” on Mars, explained Friday August 5 on franceinfo Olivier Gasnault. He is the scientific manager in France of the Franco-American ChemCam instrument, one of the ten instruments on the Rover Curiosity which arrived on Mars ten years ago, on August 6, 2012.

PODCAST >> Mars, the new odyssey

The activity of the Martian explorer robot has once again been extended by NASA until September 2025. Curiosity will head for a new area of ​​the red planet in order to continue its explorations.

franceinfo: Curiosity’s mission was supposed to last two years, but in the end it’s been ten years and it will continue until 2025. What’s next?

Olivier Gasnault: It is a significant investment and we are happy to be able to use it for so many years and to continue to explore the surface of Mars. The advantage of extending the mission is in particular that we are at the foot of a mountain which is 5,000 m high and there is no question of going to the top but the first strata tell us about the evolution of the environment on the surface of Mars. We try to understand the transition to an arid passage.

Is this what is likely to happen to the Earth with global warming?

We are on very different geological time scales, the earth problem is much more immediate. The transformations on Mars go back much further in the past and took place over many years, we are talking about millions of years. It is a more global change of the planet, including the magnetic field of the atmosphere and therefore the presence of water on the surface.

How do you explain the longevity of this robot?

We have teams of engineers who have developed great tools both on the Rover and on instruments like ChemCam. The objective of two years was the minimum and to reach it we are obliged to develop more robust techniques which allow this longevity. We now want to pay attention to how we use these instruments to preserve them as long as possible. This is a gain for the scientific return of the whole community.

What does the ChemCam instrument on Curiosity do?

It is a chemical camera that maps around the American Rover the chemical composition of the rocks that make up the Martian soil to understand this geological context. This helps to understand how rocks were transformed by water more than three billion years ago when life appeared on Earth and there was liquid water on the surface of Mars. ChemCam’s vision will be to understand the chemical composition of these rocks, what are their origins from a magmatic point of view, their transformation with water. We have been able to show that there were several episodes with liquid water on the surface of Mars which transformed these rocks.

How did you decide on the exploration area?

This is work that was done before selecting the landing site to find a site where we had the best chance of having interesting results on the fact that there was water, the place could have been habitable and on the organization of the geological layers which makes it possible to establish a chronology.

Then, we have limited travel capacities, there is no road, we are very far away and we make a lot of observations as we go along. We have covered a little more than 28 km in ten years and there is no question of going completely elsewhere on Mars. We continue our ascent of this mountain which allows us to move forward in the history of Mars. We hope to explore a few million years through these few kilometres.

What have we learned in ten years?

The first result was to show the habitability of this region 3.6 billion years ago. If there had been a very simple, single-celled life form, it could have survived under these conditions for a few million years. It has been shown that these environmental conditions have evolved into a drier climate, that water has moved underground. We are now studying this transition, we have also been able to show that perhaps we had the emergence of a continent on the surface of Mars.

Finally, there are studies of the modern atmosphere that are being done with a Spanish climate-studying instrument to see how it compares with the past climate of Mars and what the radiation conditions are on the surface.