Mason outlines the process that was required to build the Perseverance rover emphasizing how the rover was built one layer at a time, "like an onion, with everything cleaned before it is added." These extreme methods are taken in order to limit the bacteria, viruses, fungi, or spores on equipment to be sent on a mission.
"But, it is almost impossible to get to zero biomass on a spacecraft. Microbes have been on Earth for billions of years, and they are everywhere. They are inside us, on our bodies, and all around us. Some can sneak through even the cleanest of clean rooms," argues Mason.
As such, says the scientists, experts must take measures to ensure any life they find on foreign planets is indeed of a foreign source. It is quite possible that the life spotted on Mars could be from an entity that survived on the crafts sent to the Red Planet.
"But even if Perseverance — or the missions that preceded it — did accidentally carry organisms or DNA from Earth to Mars, we have ways of telling it apart from any life that is truly Martian in origin. Hidden within the DNA sequence will be information about its provenance," explains Mason.
This transfer of microbes is not all bad, further explains Mason. In fact, he argues that when we come to land someday on Mars our microbes will help us survive there. The key however is to be able to distinguish what comes from Earth and what comes from the Red Planet.
The Mars Perseverance Rover mission made its way to the Red Planet on July 30, 2020. The Mars 2020 Perseverance is now hunting for microscopic life using a precision X-ray device — called PIXL — powered with artificial intelligence (AI).