Finding signs that once there was life on Mars could be easier soon.
This is what scientists who control the unmanned NASA mission that must hit the red planet in 2021 with the specific goal of trying to find evidence of past life.
The six-wheeled vehicle that will run through Mars will look for tracks on rocks that may be about 3.9 billion years old.
Confirming that there was life on Earth at such a remote time is very difficult, but researchers believe that on Mars the evidence can be better preserved.
This is due to the dynamic processes that exist on our planet that constantly agitate and recycle the rocks, which can erase the vestiges of life, but which in the red planet stopped at an early stage of its history.
"We do not believe, for example, that Mars had tectonic plates like Earth has for most of its history," says Ken Williford of NASA's Jet Propulsion Laboratory in California. acronyms in English).
"Most of the record of Earth's rocks was destroyed by subduction under the oceanic crust, but even the rock that remained on the surface was heated and crushed in ways that should not have happened on Mars. So, paradoxically, it is likely that the oldest rocks on Mars are better preserved than the young rocks on Earth, "he told BBC News.
Traces of water and life
The exploration vehicle will carry out its work near the Jezero Crater, which satellite observations suggest once housed a deep lake.
Scientists hope that if microbes lived in or around this body of water, there were traces of their presence preserved in sediments that can now be easily drilled.
One of the main targets will be the carbonate deposits that seem to line up with what would have been the old shoreline of the lake.
"Carbonates are a type of mineral that plunges out of the water and what's really good about it is that when they take everything in the water. So all life there can get stuck inside the ore, "explained Briony Horgan of Purdue University in Indiana.
The ideal scenario would be for the vehicle to find formations that look like stromatolites. These are dome-shaped carbonate structures that on Earth were built by microbial mats.
The vehicle will choose between the most tempting place along the alleged coastal strip and drill samples that can be packed in a container and left in the soil to be collected later.
NASA and its European counterpart ESA are planning a joint project to recover up to 40 samples of the vehicle, probably in the early 2030s.