The prospect, no matter how remote, that a space probe launched from Earth may “contaminate” another planet with Earthly microbes, is concerning some scientists, especially once technology allowing unmanned spacecraft to travel to nearby star systems is developed.

However far in the future such technologies may be, it is worth thinking about the potential problem of contaminating other solar systems with Earth life, according to a new paper by Charles Cockell of the Centre for Earth, Planetary, Space and Astronomical Research at Open University in Milton Keynes, UK. Why should we take the trouble to avoid such interstellar contamination? First, there is the “utilitarian desire to preserve examples of other life of potentially enormous scientific interest”, Cockell says. In previous writings, he has also argued that humans have an ethical responsibility to avoid harming life in other solar systems.

Special care was taken to ensure that the Phoenix Mars lander was sterilised lest its robotic digging arm somehow seed the Martian soil, while the chances of deep space probes such as the Pioneer or Voyager missions crash landing on a distant planet somewhere, and spawning life, are extremely unlikely.

But there may be a B grade science fiction horror movie synopsis here however.

Earth originating space probe crash lands on distant planet, spawns some sort of mutant life form which then makes its way back to the Solar System to terrorise the people of planet Earth.

Any takers?