When it comes to searching for evidence of life on Mars, there’s one material that is particularly important: Clay. Clay minerals are formed in the presence of water, and could once have been home to microscopic life on Mars. That means they are a key target for NASA missions like the Perseverance rover which is currently on its way to the red planet.
Now, scientists have investigated a similar environment on Earth which could give clues to finding evidence of ancient martian life. Researchers from Cornell University went to the Atacama Desert in Chile, the driest place on Earth, to look at the soil there. They found that about a foot below the surface, there was wet clay which was home to life.
“The clays are inhabited by microorganisms,” corresponding author Alberto G. Fairén, a visiting scientist in the Cornell Department of Astronomy, said in a statement. “Our discovery suggests that something similar may have occurred billions of years ago — or it still may be occurring — on Mars.”
This is important for the Perseverance rover’s mission to find evidence of ancient life on Mars. The rover will use instruments like spectrometers to analyze samples of rock from the martian surface and look for indicators like unusual layers which could indicate there was once life on the planet, millions of years ago.
“This paper helps guide the search,” Fairén said, “to inform where we should look and which instruments to use on a search for life.” It will also inform the search performed by Europe and Russia’s Rosalind Franklin rover, which is set to launch in 2022.
Both rovers will look for fossilized microorganisms beneath the martian surface, which is known to have clays in some areas. This indicates that not only was water present there once, but there could also have been the conditions for life to thrive. “That’s why clays are important,” Fairén said. “They preserve organic compounds and biomarkers extremely well and they are abundant on Mars.”
The research is published in the journal Nature Scientific Reports.