On April 11, the Israeli lander Beresheet ("in the beginning") crashed on the moon, spilling precious cargo that included a copy of the entire English-language Wikipedia, a sample from India's sacred Bodhi tree, and several thousand dehydrated tardigrades. Despite the lander's 300-MPH collision with the surface, reason to think the millimeter-long tardigrades survived. And to some scientists, the implications are as enormous as the “water bears” are microscopic.
As Wired reported on August 5, the tardigrades hitched a ride on a lunar library ̵
The tardigrades were sandwiched between the sheets while suspended in epoxy, a resin-like preservative that acted as the jelly. It is the added bulk of the dried epoxy that may have led to the library's survival as well as its tardigrades.
Did They Survive?
Tardigrades are notoriously hardy, with the ability to enter a dormant state through a process called cryptobiosis . When faced with adverse circumstances, like a crash landing on a lifeless rock in space, a tardigrade becomes a “tun” – a dehydrated shell of itself with a metabolism close to nil. In this state, it can survive for over 30 years, well above its normal two-year lifespan, yet it is still able to rehydrate and reproduce when conditions are right.
At this point it is impossible to confirm whether the tardigrades made it through the Beresheet crash, though if they did, it would be the first time they had survived in space.
Tardigrades Have Survived Space Before
Aboard the FOTON-M3 mission that launched in September 2007, two species of dehydrated tardigrades were exposed to the dehydrating vacuum of space, solar radiation, or both. When they were rehydrated on Earth, those who had only been exposed to the vacuum went on living as if nothing had happened; some even went on to reproduce, as a Current Biology paper on the discovery detailed.
"Our [principal] finding is that the space vacuum, which contains extreme dehydration and cosmic radiation, was not a problem for water bears," said Ingemar Jönsson, Ph.D., project leader of TARDIS (short for Tardigrades in Space), at the time. Only a few, however, survived exposure to solar radiation.
Then there was the group of tardigrades that hitched a ride to the International Space Station in May 2011 as part of the Italian TARDIKISS experiment, which showed that a microgravity environment did not change some physiological aspects of the animals.
In January 2012, a group of tardigrades was bound for the Martian moon Phobos, but the launch failed. The passengers onboard Beresheet, if they made it, will be the most recent that we successfully sent to the moon.
Colonization Is Unlikely But Still Problematic
The TARDIS experiment showed that tun-state tardigrades exposed to a space vacuum can reproduce – but only after being rehydrated. Since Beresheet's lunar library is likely to come into contact with water on the moon anytime soon, it is even less plausible that they will reproduce and colonize it.
They should resurrect. "
" They cannot colonize the moon because there is no atmosphere and no liquid water, "University of Poznań astrobiologist Lukasz Kaczmarek, Ph.D., told the Guardian . “But it could be possible to bring them back to Earth and then add the water. They should resurrect. ”
That said, the more possibility of colonization – by tardigrades, or any future species surviving a lunar crash – that has some people concerned about the future of space exploration. In a Twitter thread Monica Vidaurri, a science consultant for NASA's Goddard Space Flight Center, argued that the accidental spillage of tardigrades on the moon – and the largely unconcerned public response – was a consequence of the absence of much "It is the result of a major gap in accountability for planetary protection and ethics between public and private science, and we have no idea what can happen as a result," she wrote.
This carelessness, she argues, is the result of a colonial mindset that has led humans to think acceptable to impose ourselves on other environments, both on or off Earth.
“Colonialism. But imperialism. Not for us. And if our science carries on under the same institutions of imperialism, in the name of the same government and not for all of humanity, it is not science, ”she tweeted .
The Arch Mission Foundation, for its part, is already planning to send another version of the lunar library to the moon aboard a lander operated by the private company Astrobotic. Whether it will carry dormant organisms, however, remains to be seen.
The 1967 Outer Space Treaty, the first global set of lunar laws, established the moon as a "global commons" rather than a new parcel of land up for grabs. It was signed by spacefaring nations, including the US and the Soviet Union, who at the time "agreed that" colonization "on Earth had been responsible for tremendous human suffering and many armed conflicts that had raged over the last centuries," as University of Nebraska-Lincoln professor of space law Frans von der Dunk, Ph.D., wrote in the Conversation .
The Treaty includes the line "States should avoid harmful contamination of space and celestial bodies," but in the future it will be up to space lawyers to define what exactly constitutes "harm."
While tardigrades from the Beresheet crash may have survived, they seem unlikely to reproduce on the moon. They do, however, represent a certain carelessness for space on humanity's part, and as we prepare to travel back to the moon and even deeper into the solar system, potentially bringing life to even more remote worlds, it's up to us to collectively decide if we care to contain our spread or not.