Keeping microbes off the moon involves a lot more than handwashing, but fewer photos. (Photo by Gentle07)

As I wrangle more conversations into a shareable format for our sci-fi film festival (thanks for your patience), let’s return to a sci-fi topic encroaching on our reality: extraterrestrial life. Many of us have space travel on the mind, especially this week as we celebrate the first all-female space walk. (I suppose once upon a time that might have seemed purely sci-fi itself.) We have plans to return humans to the Moon, and a vision to set foot on Mars as well. Yet we need to be wary of stowaways, particularly bacteria and other microbes. They get everywhere and can be quite challenging to get rid of. Nevertheless, if we want any future claims about life on Mars to be taken seriously, we need to make sure it was there before us.

I mentioned this problem in another recent post about the possibilities for life on Mars. This week’s news reveals NASA is updating the protocols for preventing contamination of other celestial bodies with microbes from Earth. Biology has come a long way in the ~50 years since the protocols were instituted, including the entirely genomics revolution. Improved sequencing technology has revealed whole swaths of microbes previously inaccessible because they can’t be cultured in the lab. So we can now detect contamination more sensitively, showing us just how ubiquitous bacteria can be. Full prevention may not be possible; instead, we might consider accepting that some will inevitably occur and instead focus on restricting it to those portions of the Moon and Mars where native life is least likely to be found.

Actually, contamination may have already happened after a fashion. A couple of months ago, there were wide reports of a crash on the Moon that may have released tardigrades. Tardigrades are impressively hardy microscopic animals, which inspired curiosity about how they’d fare in the lunar environment and if they could be revived from their dormant, dehydrated state once they returned home. But the lander carrying them crashed, potentially initiating a different sort of experiment than the one intended. Rehydration requires water, which is hardly abundant on the Moon, so it is not as if there are active tardigrades crawling around. Still, it illustrates the risk that contamination is possible.

And if we’re updating the status of life on Mars, a former NASA scientist got a significant platform from Scientific American to describe results from a 1976 mission that he feels indicate the presence of living organisms. I think skepticism is certainly warranted; he has been making these claims for over twenty years and has not persuaded a large number of scientists. At the same time, the primary counter position is that the data are not definitive evidence of life, rather than an assertion that the data contradict the possibility of life. I do imagine we’ll have a lot more of this sort of “most likely no, but not definitely no” evidence before we get any conclusive results (if ever). For some that may be frustrating; for scientists, that’s the exciting part because there is still a puzzle to solve.

Next week, several contributors to Science & Faith, the book developed from the STEAM-funded blog series on student questions, will be hosting a video chat on fostering conversation on these topics. Details are here; check it out if you are able.

If you will be in the Princeton, NJ area this weekend, I’ll be speaking at Stone Hill Presbyterian at 7pm on Saturday (10/26/19). Details are here. As always, it would be great to connect with you in person if you are so inclined.