Did We Just Put Tardigrades on the Moon? Probably.

The Cosmic Companion
5 min readAug 6, 2019

As far as tiny, cute, yet utterly bizarre animals go, tardigrades are almost certainly the best known. Also known as water bears, these creatures are only about a millimeter (1/25th of an inch) long, and they are known to survive in extreme conditions, even outer space. Now, it appears thousands of these tiny creatures may now be living on the Moon.

When the Beresheet spacecraft, designed and managed by Israeli space company SpaceIL, crashed into the Moon on April 11, the collision may have spread live tardigrades on the lunar surface.

A tardigrade seen in a microscopic photograph. Image credit: University of Oxford

“For the first 24 hours we were just in shock. We sort of expected that it would be successful. We knew there were risks but we didn’t think the risks were that significant,” Nova Spivack, founder of the Arch Mission Foundation, stated. It was his organization which designed the tardigrade payload.

The robotic lander included thousands of tardigrades (as well as human DNA) encased in resin between layers of nickel, much like an insect trapped in amber between layers of metal. Tape used in holding the biological time capsule in place was also coated with thousands of tardigrades. It is unknown whether the tiny creatures survived the crash, although they are among the most resilient creatures on Earth.

Making the Tardigrade

Normally, these creatures make their home nearly anywhere, although they prefer wet environments like beds of moss. Sediment at the bottom of lakes is a favorite habitat. They are also the only creatures known to be able to survive the harsh environment of space.

Also known as water bears or moss piglets, these hardy creatures live at temperatures as low as -200 Celsius (-328 Fahrenheit), or as high as 150 C (300 F). They survive pressures six times greater than the greatest depths of the ocean, and are highly resistant to radiation and boiling liquids. One study subjected these creatures to the conditions of low Earth orbit for 10 days, and these tiny animals survived the ordeal.

Tardigrades are able to enter a state called tun, in which they expel water from their bodies, retract their legs, and wrap themselves in a tiny, protective ball for 10 years or more.

“I wish I were a waterbear — Then I’d be comfy…



The Cosmic Companion

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