It's time to update the rules. That's the conclusion of a panel that examined NASA's rules for planetary protection. It was smart, at the dawn of the space age, to think about how we might inadvertently pollute other worlds with Earthly microbes as we explore the solar system. But now that we know a lot more than we did back then, the rules don't fit.
The Planetary Protection Office (PPO) handles these rules and how they apply to spacecraft. Not just for NASA, but for other partner nations too. The Planetary Protection Independent Review Board (PPIRB) produced this new report. The PPIRB was chaired by Alan Stern, a well-known American planetary scientist, and the principal investigator for NASA's New Horizons mission to Pluto.
Whenever humans send a spacecraft to another body, there's a risk of contaminating that body with microbes from Earth. Eliminating or lowering that risk is the only way to guarantee integrity in the search for life. Great pains are taken to sterilize spacecraft, but the risk is never zero. Spacecraft are prepared in sterile clean rooms before launch, and back in the 1970s, the Viking landers were sterilized in huge ovens built just for that purpose.