Forward contamination, in the context of planetary protection, refers to the transport of microbes from Earth to Mars. The title of the workshop, and many talk titles refer to “human extraterrestrial missions,” but really, we’re talking about sending astronauts to Mars to walk on the surface of Mars, drill holes in Mars, scoop up dirt from Mars, and then returning the astronauts to Earth. There was almost no talk about human habitation on Mars. First things first, I suppose.
So, John Rummel kicked things off with a brief history of planetary protection. The gist of it is that, because we at some point deemed the moon devoid of life and uninhabitable, we didn’t think much about planetary protection until we started exploring Mars. In 1991, the stance on planetary protection was basically, “Viking didn’t find life on Mars, therefore no big deal, let’s go explore.” In 2000, gullies were found on Mars, suggesting the presence of water, leading to the Pingree Park Workshop in 2005, which addressed the question: Can we explore Mars without contaminating it?
The forward contamination discussions fall into two broad categories: superbugs and human-associate microbes. First, there are some superbugs that could hitch a ride on the surface of spacecraft and find a place to grow on Mars. These are more likely to find a home on Mars, but it’s worth discussing ways to remove them from surfaces. Second, human-associated microbes are far less likely to do well on Mars, but the general consensus is that we cannot avoid contaminating Mars with them. There seemed to be a little bit of concern that they would interfere with the search for life (by providing false-positives), but most people seemed familiar enough with evolution to agree that we are not likely to mistake something with a 99% 16S rDNA sequence identity to Staphylococcus aureus for Martian life.
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