Did We Contaminate Mars? – Since the early days of Red Planet exploration, humanity has hoped to find life there. NASA reduce the risk that what we discover are creatures we brought with us from Earth.

Imagine the day when astronauts will reach the planet Mars. They will take samples from the ground and from the air and search for what fascinates mankind the most – life. But even if they find signs of life there, such as remnants of genetic material, there is a pretty good chance that it’s not from Mars, but from the spacecraft and landings we sent there from Earth.

In 1971, a man-made object landed on Mars for the first time – the Russian Mars 3 lander. Later, several other landers and robotic spacecraft successfully landed on Mars. They probably brought bacteria from Earth, and perhaps some of the bacteria survived the long journey in the hostile conditions of space.

Many studies by the U.S. space agency NASA address this very problem, as it has multiple and dangerous consequences. Every spacecraft that NASA launches undergoes a rigorous cleaning process as much as possible in disinfected and cleaned spaces. But this is not enough, and even this clean environment can be invaded by other tiny bacteria and organisms (microorganisms).

Technicians clean the solar cells of the MAVEN satellite, which is currently in orbit around Mars |  NASA / Jim Grossmann.
Every spacecraft NASA launches undergoes a rigorous purification process. Technicians clean the solar cells of the MAVEN satellite, which is currently in orbit around Mars | NASA / Jim Grossmann

Two Directions for Infection on Mars

This phenomenon, of bringing living things and other forms of pollution from Earth to other planet is called forward contamination. In fact, the phenomenon is also known on Earth itself, from expeditions that have traveled to Antarctica and other remote locations. Such infection could seriously harm local populations. Moreover, contamination on Mars could skew the results of future studies.

The problem is not limited to forward contamination: at least theoretically, backward contamination could also occur. In that case, astronauts returning to Earth could bring with them an infection unknown in our world. As we saw with the COVID-19 Pandemic. A new bacterium or virus that appears unexpectedly can cause serious problems, especially if it is able to adapt to the human body or to other biological systems in Earth’s ecology.

Did We Contaminate Mars? Traces of the Curiosity SUV on the Red Planet  NASA / JPL-Caltech / MSSS.
Is that all we left on Mars? Traces of the Curiosity SUV on the Red Planet NASA / JPL-Caltech / MSSS.

We have probably “contaminated” Mars with life

The car-sized rover Perseverance landed safely on the surface of Mars on Feb. 18. It can only travel at a top speed of 152 meters per hour, but it has a suite of instruments with which it has conducted innovative experiments.

On board the three-meter-long robot is a machine that converted the thin, carbon dioxide-laden Martian air into oxygen and a helicopter that completed the first powered flight on another planet.

Microbes Might Survive the trip to planet Mars.
Microbes Might Survive the trip to planet Mars.

But is it possible that something else made it to Mars with all this equipment?

Could a trail of bacteria or spores have been accidentally transported from Earth to space. Maybe the Genetic material survived the trip to make the red planet its new home?

NASA and its engineers at the Jet Propulsion Laboratory (JPL) have precise and comprehensive protocols in place to ensure that their spacecraft are free of any organisms that might accidentally sneak into a space mission.

However, two recent studies show:

  1. Organisms may have survived the cleaning process and even the trip to Mars
  2. and how quickly microbial species can evolve in space

What would happen then if the robot finds traces of life on Mars?

The issue is very complex. We are looking for organisms that have the ability to survive in extreme conditions. That’s why we look for bacterial fossils. This type of research has to go through multiple angles of analysis.


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