How big are tardigrades

Survival in space Will tardigrade soon populate the moon?

Tardigrades - also known as tardigrades - are less than a millimeter tall, have eight legs and are important collaborators in space travel. They qualify through their ability to survive under the most extreme circumstances. The tiny tardigrade's superpowers are remarkable. It can survive boiling water, extremely low temperatures, and even radioactive radiation.

Cryptobiosis is the name given to the condition under which the little animals can endure such circumstances. The metabolic processes are extremely reduced and the oxygen consumption sinks to a hardly measurable value. They can hold out in this state for more than a decade.

Tardigrade as a spaceman

In 2017, Philip Lubin, head of the Starlight program at the University of California in Santa Barbara (UCSB), introduced the tardigrade as the first passenger on an expedition into interstellar space. He sent her on a journey beyond our solar system. For what purpose? Lubin explains this as follows: "We are developing the ability to test whether terrestrial life as we know it can exist in interstellar space." The tardigrades that were without protection in space could later be revived.

Tardigrade is now back in space. On the night of April 11, 2019, the Israeli spacecraft was supposed to land on the moon. Also on board: tardigrade. These were in the dehydrated state in the so-called lunar library of the "Arch Mission Foundation", which wants to secure knowledge and the species of the earth for future generations. Co-founder Nova Spiwack explains on the website why: "With the archive for our planet, we want to ensure that we protect our heritage - both our knowledge and our biology."

Crash on the moon

The lunar library is about the size of a DVD case and, in addition to human blood samples and the tardigrade, contains thousands of information such as the entire English Wikipedia and secrets of David Copperfield's magic tricks. The information was embossed on wafer-thin nickel discs. Seconds before the planned landing, however, the "Israel Aerospace Industry" lost contact with the space probe and fell on the moon - and with it the tardigrade.

Do you live on the moon now?

In the best case scenario, the lunar library survived the impact in one piece and is now on the lunar surface. In the worst case, it was destroyed and its contents scattered on the surface. The tardigrade was deprived of water and so they were in survival mode and could have survived and also be woken up again.

However, Spivack does not assume that the tardigrade will now colonize the moon. The dehydrated tardigrade would have to be brought to earth or to any place with atmosphere in order to be able to rehydrate, i.e. to be able to revive.

More traces of life in space

However, it was not the first time that terrestrial genetic material was left on the moon due to the possible tardigrade accident. When they landed on the moon for the first time, the space travelers left their DNA - in a garbage bag with human feces.

From the dream of the moon corn on the cob

The last time the Chinese lunar probe "Chang'e 4" left a container with plant seeds, earth, water and air, as well as fruit fly eggs and yeast on the moon on January 3, 2019: This was supposed to create a small cycle. But on January 16 the news came: The plants are dead. They hadn't survived a bitterly cold lunar night. The plants are likely to have rotted within a month, but the Chinese space agency has given assurances that the decayed material will not spill onto the lunar surface.

Stowaways on the ISS

Everything that comes from our earth always brings a bit of life with it. According to the European Space Agency, microorganisms such as viruses, bacteria and fungi were on the ISS before a human in space even stepped on it. The microbes are true survivors.

An international team of researchers led by the biologist Aleksandra Checinska Sielaff recently investigated which viable bacterial and fungal communities can be found on the surfaces in the ISS. The result: staphylococci were the most common of all microorganisms found at 26 percent. This is a bacterium that can cause infections. Whether these "stowaways" pose a threat to the human residents of the ISS remains to be investigated.