Chapter 1: The Moon's Unlikely Residents

The recent crash of Israel’s privately funded Beresheet spacecraft on April 11 has sparked curiosity about its cargo, particularly a collection of tardigrades. These microscopic creatures, known for their resilience, were part of an archive created by the Arch Mission Foundation, designed to preserve human culture for eons. This disk contained numerous pages of microscopic text and digital copies of English Wikipedia, alongside preserved biological material, including hair from the engineering team and thousands of tardigrades.

Given the notorious durability of tardigrades, Arch Mission co-founder Nova Spivack pondered whether he had inadvertently introduced life to the lunar surface. Experts indicate that while the conditions on the Moon are largely unfriendly to tardigrades, some may have survived the impact. However, this doesn't imply that the Moon hosts life as we typically understand it.

“I hesitate to say they are ‘surviving’ because these tardigrades are in a dormant state,” remarks Mats Harms-Ringdahl, a professor emeritus at the University of Stockholm. “They possess the potential to revive, so to speak.”

Tardigrades, often referred to as “water bears” or “moss piglets,” typically thrive in moist environments. While many species inhabit aquatic settings, some have adapted to terrestrial life. In fact, with a simple microscope, one could likely find them nestled in the moss or lichen of local parks. When water is abundant, they feed, reproduce, and lay eggs; however, during droughts, they enter a desiccated state known as “tuns.”

Though dehydration can lead to death in any species, tardigrades are unique in their ability to revert to a more active state after drying out. This remarkable trait positions them as some of the most adept survivors in the animal kingdom, with studies showing they can revive even after extreme conditions, such as freezing temperatures and immense pressure. Some tuns have been rehydrated after nearly a decade, while others have survived up to 30 years without sustenance.

Given these capabilities, the tuns transported by Beresheet—some encased in tape and others preserved in resin—might have reached the lunar surface intact, assuming the crash did not generate excessive heat. However, Harms-Ringdahl warns that exposure to temperatures nearing 200 degrees Fahrenheit could damage their proteins, potentially leading to permanent dormancy.

Even those tardigrades in a state of suspended animation may not be safe on the Moon for long. Harms-Ringdahl, who investigated the effects of radiation on tardigrades, recalls a European mission that uncovered their vulnerability to solar radiation. In this study, tardigrades were launched into low Earth orbit for ten days. While some were shielded from ultraviolet rays, others faced unfiltered sunlight. Upon returning to Earth, the protected tuns revived successfully, whereas those exposed to direct sunlight remained lifeless. This sensitivity to UV light poses a significant risk for any tardigrades resting on the lunar surface. “Even DNA is susceptible to UV radiation,” Harms-Ringdahl explains, “and the Moon’s lack of atmosphere intensifies this threat.”

With lunar days and nights lasting about two weeks, it’s likely that the remnants of Beresheet have been exposed to significant sunlight since the crash. Nevertheless, the tuns might still have a chance if they landed beneath a layer of lunar dust.

“If the tardigrades are directly exposed to full-spectrum UV light, they will perish in a matter of days, with no hope of revival,” states Ingemar Jönsson, a professor at Kristianstad University and a leader in tardigrade research. “However, if buried in cooler, shaded conditions, they could potentially survive for years.”

The critical factor now is the condition of the archival disk that houses these tardigrades. At launch, it was insulated by numerous layers of reflective nickel and metallic heat shields, which may help maintain a stable environment. However, any damage incurred during the crash could compromise the creatures' protection from heat and UV exposure. Only future lunar explorations can provide definitive answers.

Space is a harsh environment for unprotected organisms, and if the water bears have succumbed to the Moon's intense UV radiation, it would not be unexpected—after all, even robust bacterial spores struggle against prolonged exposure. If the Arch Mission Foundation aims to establish life on the Moon, they might want to broaden their selection of candidates. There exists at least one life form that can withstand direct sunlight in open space, one that tardigrades are well-acquainted with. Next time, including a lichen could be beneficial.

Chapter 2: The Search for Survival

This video explores the possibility of tardigrades being the first forms of life on the Moon and discusses their unique survival abilities.

In this video, we delve into the intriguing idea that tardigrades may still be alive on the Moon following the crash, examining their resilience in extreme conditions.