SpaceX's launch of a Tesla Roadster into deep space may have got 10 out of 10 for style and PR, but it looks as if it got one out of 10 for cleanliness. According to scientists at Purdue University, the electric sports car and its plastic mannequin driver may be the dirtiest unmanned objects ever launched into orbit – carrying an unprecedented amount of bacteria that could one day contaminate Mars.
Anyone who's ever bought a second-hand car knows that they're likely to find unpleasant surprises under the seats or tucked in the glove box. In fact, if you were to commission a forensic analysis of the average used vehicle with its collection of skin flakes and dried mucus, you'd probably never get into another one without a hazmat suit on.
Not surprisingly, spacecraft tend to be a bit more hygienic. International agreements require any unmanned probe that is likely to land on another planet, moon, asteroid, or other celestial body meet rigorous sterilization standards inside and out to minimize the chance of terrestrial microbes ending up colonizing another world. At the minimum, this would complicate the job of scientists seeking alien life, but it could have worse effects.
"If there is an indigenous Mars biota, it's at risk of being contaminated by terrestrial life," says Jay Melosh, a professor of earth, atmospheric and planetary sciences at Purdue. "Would Earth's organisms be better adapted, take over Mars and contaminate it so we don't know what indigenous Mars was like, or would they be not as well adapted as the Martian organisms? We don't know."