ARI SHAPIRO, HOST:
There may be life on the moon, and humans may have put it there. In April, a failed lunar mission crash landed and spilled its cargo of a few thousand tardigrades. Tardigrades are tiny, adorable to some, and one of the toughest creatures around. Daniel Oberhaus wrote about the failed lunar mission for WIRED Magazine.
Welcome to ALL THINGS CONSIDERED.
DANIEL OBERHAUS: Thank you for having me.
SHAPIRO: I'm embarrassed to say I'd never heard of a tardigrade before this story. What are they?
OBERHAUS: So these are microorganisms. They're a little under a millimeter in size. They have four legs. And a lot of people think they look like bears, hence the name water bear. They are found everywhere on Earth, from jungles, to the top of the Himalayas, to the Antarctic. And as you had mentioned, they can survive pretty much any sort of environment, from extremely hot temperatures to extremely cold temperatures. They can survive in the vacuum of space. They're pretty much indestructible.
SHAPIRO: And how did a few thousand of them potentially end up on the moon?
OBERHAUS: A non-profit organization called the Arch Mission Foundation sent a lunar library to the surface of the moon with the Beresheet lander.
SHAPIRO: The Beresheet lander. This is an Israeli mission.
OBERHAUS: Yes. And on this lander, there is a disc about the size of a DVD made of several ultrathin layers of nickel. And sandwiched in between those layers of nickel are thin layers of epoxy that contain DNA from humans in the form of hair follicles and blood samples as well as several thousand tardigrades.
So the idea here was to - in addition to all the digital information stored on the layers of nickel - was to preserve biology from Earth.
SHAPIRO: And if the tardigrades did survive this crash landing, are they still sandwiched in this kind of DVD type thing?
OBERHAUS: That's the hope. No one knows for sure. They did some mathematical modeling after the crash and determined that in all likelihood, this disc was actually probably the only thing that survived the crash. So there is a pretty good chance that there are tardigrades on the moon.
SHAPIRO: Does that matter? I mean, are they going to, like, breed and take over the moon? I mean, is it some kind of moon pollution? Like, what's the importance of this?
OBERHAUS: Yeah, so there's no reason to worry about tardigrades becoming our lunar overlords anytime soon.
SHAPIRO: (Laughter).
OBERHAUS: They are - they're in a state of - it's called cryptobiosis, which is where they actually shed all the water in their cells. They tuck in their legs, and they almost turn into a glass. And they can last for decades in this form. But they can't reproduce. Their metabolism all but stops. So they're there. They're kind of alive depending on your definition of life, but until someone were to bring them back to earth, they're not going to be moving around or doing anything like that on the moon.
SHAPIRO: OK, so this seems relatively harmless. But this was a privately funded lunar mission. What's to stop some other billionaire from crash landing something on the moon that's not as harmless as a tardigrade, that could actually, you know, do real damage?
OBERHAUS: I think that's a concern for a lot of people. The fortunate thing, I suppose, is that the moon is considered a relatively low risk for this sort of thing. When the Apollo astronauts went there 50 years ago, they left dozens of bags of human excrement on the surface of the moon, so they were the first to actually leave DNA there.
But I think looking to the future, this is something we need to discuss with private missions to places like Mars where introducing DNA into that environment could potentially contaminate the science that they want to do to perhaps find traces of life. So, you know, I think it's a great entryway for this discussion about who gets to determine what is placed on other celestial bodies.
SHAPIRO: Well, you know, compared to bags of human excrement, I think I would prefer a few thousand tardigrades. Reporter Daniel Oberhaus speaking with us on Skype. He wrote about the possibility of tardigrades on the moon for WIRED Magazine.
Thank you.
OBERHAUS: Thank you, Ari.
[POST-BROADCAST CORRECTION: This report incorrectly says that tardigrades have four legs. They actually have four pairs of legs.
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