A digital library carried by the Israeli lunar lander, Beresheet, that crashed on the Moon in April also carried with it dehydrated tardigrades, also called water bears.
Spivack had planned to send DNA samples to the moon in future versions of the lunar library, not on this mission. But a few weeks before Spivack had to deliver the lunar library to the Israelis, however, he decided to include some DNA in the payload anyway. Ha and an engineer on Spivack’s team added a thin layer of epoxy resin between each layer of nickel, a synthetic equivalent of the fossilized tree resin that preserves ancient insects. Into the resin they tucked hair follicles and blood samples from Spivack and 24 others that he says represent a diverse genetic cross-section of human ancestry, in addition to some dehydrated tardigrades and samples from major holy sites, like the Bodhi tree in India. A few thousand extra dehydrated tardigrades were sprinkled onto the tape used to secure the lunar library to the Beresheet lander.
The promising thing about the tardigrades, says Spivack, is that they could hypothetically be revived in the future. Tardigrades are known to enter dormant states in which all metabolic processes stop and the water in their cells is replaced by a protein that effectively turns the cells into glass. Scientists have revived tardigrades that have spent up to 10 years in this dehydrated state, although in some cases they may be able to survive much longer without water. Although the lunar library is designed to last for millions of years, scientists are just beginning to understand how tardigrades manage to survive in so many unforgiving environments. It’s conceivable that as we learn more about tardigrades, we’ll discover ways to rehydrate them after much longer periods of dormancy.
They suspect that the digital library probably survived the crash, which means the dehydrated water bears did also.
Don’t expect the Moon to be overrun by tardigrades. However, it will be a very interesting discovery if we find, years hence when explorers finally can recover that digital library, that the tardigrades can be re-hydrated and come back to life.