Planetary protection is a major challenge to avoid extraterrestrial contamination
– News of February 3, 2019 –
We hope to find traces of life on the planet Mars, on Europe the moon of Jupiter, or on some other bodies of the solar system. To achieve this, we send robots to the surface of these bodies. So we take the risk of sending terrestrial microorganisms. Our planet is so teeming with life that even the smallest cubic centimeter of air or any exposed surface is full of bacteria and microbes. If we discover a microorganism on the planet Mars, we have to be sure that it is a local species and not a stowaway brought by the rover. We must also be sure not to commit genocide on a planetary scale by landing a new dominant species on these celestial bodies.
To avoid possible contamination, space agencies therefore follow planetary protection guidelines. This involves decontaminating robots for space exploration. For this reason, for example, the Cassini spacecraft was thrown into the atmosphere of Saturn in September 2017. This ensures that it will not hit any of the frozen moons of Saturn, which are thought to potentially harbor life.
Of course, planetary protection also works in the other direction. When an extraterrestrial sample is brought to Earth, it is important that it does not contain any form of extraneous life. The few samples that have been collected on the Moon or other celestial objects are kept in specially designed laboratories to avoid any contamination in one direction or the other. This is called the precautionary principle. Indeed, we don’t know about the ability of terrestrial microorganisms to survive outside the Earth, and neither about the survival capabilities of potential extraterrestrial microorganisms. To monitor this, some space agencies like NASA are recruiting specialists, planetary protection officers.
Mankind has already seen many times how the arrival of a new species can upset an entire ecosystem. For example, the arrival of the Asian hornet in Europe has had many impacts. Therefore it seems important to try to avoid reproducing the same phenomenon on a planetary scale.
Picture by Nasa [Public domain], via Wikimedia Commons
