Tardigrades on the Moon

The lander crash-landed on the surface of the Moon on April 11, 2019 due to technical problems and hit the surface at more than 3,000 km/h.[6]

Tardigrades can withstand extremely low temperatures close to absolute zero[7] and high temperatures over 400 K.[8] In comparison, temperatures on the Moon range from 140 K at night to 400 K during the day.[9] They are also able to survive large doses of ionizing radiation and the vacuum of outer space.[8][10][3]

Tardigrades can undergo all five types of cryptobiosis, reducing their metabolism to less than 0.01% and their water content to 1% compared to their normal state.[8][11] They can be revived from this state even decades later.[12]

In 2021, researchers at the Queen Mary University of London placed tardigrades in hollow nylon bullets and fired them into sand targets. The tested tardigrades were able to survive impacts of up to 3,000 km/h and momentary shock pressures of up to 1.14 GPa. The results suggest the tardigrades were unlikely to survive the crash because the shock pressure of the lander's metal frame hitting the surface would have been well above 1.14 GPa.[11]

The possibility of surviving tardigrades raised concerns about possible contamination of the Moon with biological material.[6] If recovered and hydrated they could be awakened, but this is unlikely to happen because of the lack of liquid water on the Moon.[12]

Spilling tardigrades across the Moon is legal.[13][14] The Outer Space Treaty only explicitly bans weapons and experiments or tools that could interfere with other missions.[1] Large space agencies typically follow guidelines for sterilizing mission equipment, but there is no single entity to enforce these rules globally.[12]

• Animals in space
• List of microorganisms tested in outer space
• List of species that have landed on the moon