The moon is littered with human artifacts, remnants of previous missions. For example, there are more than 100 items in the Sea of Tranquility, which includes shovels, rakes, television cameras, a plaque, human waste and more. International agreements require government agencies to be careful to thoroughly sterilize anything that goes into space or to another world, though, in order to prevent contamination of pristine worlds.

Unfortunately, because of the crash of an Israeli lander in April, it is possible that an Earth organism has contaminated the moon: dehydrated tardigrades, the microscopic animals commonly called “water bears.” Such contamination could negatively affect future astroarchaeologists or astrobiologists working on the Moon.

Water bears are known for their resilience, and their ability to survive in harsh conditions that are lethal to other forms of life. They got their name because they look like microscopic bears with their plump tiny bodies and stubby legs.

The spacecraft was slated to be the first private spacecraft to land on the moon, landing in the Sea of Serenity, and was to deposit a digital time capsule that included a “starter guide” to humanity: DNA samples, thousands of books in a DVD-sized nickel digital archive which included textbooks, and water bears. When the spacecraft crashed, Nova Spivack, who founded the Arch Mission Foundation, a nonprofit whose goal is to create “a backup of planet Earth,” wondered if he had just littered the moon’s surface with water bears.