Did any of them survive the impact? If they did, what happens to them now?
The tardigrades were in a tun state when they were placed on the Israeli moon mission Beresheet—ddehydrated, with their chubby limbs and heads retracted, and with all metabolic activity temporarily suspended. Their arrival on the moon was unexpectedly explosive; Beresheet’s April 11 crash landing may have scattered the microorganisms on the lunar surface.
Tubby tardigrades are known to be tough, but were the Beresheet tardigrades tough enough to withstand the impact? It’s possible that some of them made it to the moon unscathed. But what would it mean for the moon to have thousands of Earth microbes as new residents? What does this mean for tardigrades?
First and foremost, is anyone in hot water for accidentally spilling tardigrades on the moon? That’s a complicated question with a simple answer: no. According to the 1967 Outer Space Treaty, space agencies from around the world follow a decades-old treaty about what is permissible to leave on the moon, and the only explicit prohibitions are against weapons and experiments or tools that could interfere with missions from other agencies.
Tardigrades, which are found on every continent, are now (possibly) living on the moon, thanks to the crash of a lunar lander carrying thousands of the microscopic water bears.
Sole survivor
Tardigrades survive conditions that would kill most other organisms by expelling water from their bodies and producing compounds that seal and protect their cell structure. The creatures can remain in this so-called “tun state” for months and still resurrect when exposed to water; in 2016, scientists resurrected two tardigrades from a 30-year deep freeze.
A tardigrade, like a tun, can withstand boiling, freezing, high pressure, and even the vacuum of space, according to the European Space Agency (ESA), after sending water bears into orbit in 2008. The tardigrades’ kryptonite turned out to be ultraviolet radiation, as few of the creatures survived full exposure to UV light during the ESA experiments.
