NASA scientists have identified the necessary depth of digging the soil on Mars to search for extraterrestrial signs of life. The results of the study are published in the journal Astrobiology.
According to the calculations of experts, the Curiosity rover will have to penetrate to a depth of about two meters to find at least some traces of living microorganisms. They came to such conclusions by calculating that ionizing radiation from space destroys small molecules (for example, amino acids, which are the basis of proteins) rather quickly. Exposure to water and perchlorates further accelerates the rate of degradation.
At the moment, the rovers go only five centimeters deep, and at such a depth all the amino acids would be destroyed in just 20 million years. This is a fairly short period of time on a cosmic scale, since traces of ancient life on Mars could have existed billions of years ago, when the planet was similar to Earth.
Despite the fact that amino acids have not yet been found on Mars, they have been recorded on various meteorites, including those from Mars. According to scientists, meteorites break off the planet from a depth of at least one meter, so the amino acids at these objects were protected from cosmic radiation.
In June 2022, Canadian researchers at McGill University identified microorganisms on Earth that are able to survive in extreme conditions similar to Martian conditions.