Scientists make plans to keep spacefarers from contaminating other worlds Premium

Interplanetary contamination risks from space missions and strategies to mitigate them, including the importance of safeguarding extraterrestrial environments.

In his inauguration speech in January, United States President Donald Trump declared the US would “plant the stars and stripes on the planet Mars”.

This shouldn’t come as a surprise. In 2017, in Trump’s previous term of office, he promised to “establish a foundation for an eventual mission to Mars”. And his billionaire adviser Elon Musk is famously obsessed with colonising the red planet.

The first spacecraft to successfully explore another planet was NASA’s Mariner 2 mission. It passed within 35,000km of Venus on December 14 1962. Since then, there have been many successful missions to explore various planets, moons, asteroids and comets in the Solar System.

But in our quest to explore celestial bodies, we risk contaminating them. And if we were to inadvertently contaminate a world that has the potential to host life – either now or in the past – that could compromise all future scientific investigations. It could also affect any life that may currently exist there.

Because of this, space agencies such as NASA take the issue of interplanetary contamination very seriously. To decrease the risk, it uses a range of methods. And scientists are developing new ways to ensure biological material from the earth doesn’t make its way onto another planet.

Interplanetary contamination refers to a scenario in which a spacecraft carries biological material from one planetary object to another. Research indicates previous missions to Mars may have contaminated it with bacterial spores from the earth.

There are two types of interplanetary contamination.