by Alexa (age 9, @KNEstemGirls)

Have you ever seen or heard of a tardigrade? They’re super cool! These microscopic critters (also known as water bears or moss piglets) are the toughest creatures on earth. These extremophiles* can survive temperatures down to absolute 0 and up to 300° F, be exposed to 1,000 times the radiation that would kill an elephant, and withstand pressures up to 6 times of what you would find in the deepest parts of the ocean (I am not joking, if you want information or proof, google tardigrade or click on this link to a SciShow about tardigrades).


In 2007, a spacecraft took a bunch of these creatures into outer space for 10 days and when they came back, the tardigrades were perfectly fine. Some of them even had little tardigrade babies! So we keep doing it. At one point, the European Space Agency sent some tardigrades into space as a mission, called Tardigrades in Space (they shortened it to TARDIS, which is clever if you watch Dr. Who).

Unless you have a microscope, you won’t be able to see one, but if you do, a tardigrade has a plump body and little legs that look like circles. If you look very closely, you might be able to see their claws, but if you look closer you just might be able to make out all 4 of them.

If you want one as a pet, then I would suggest looking in moss. If you have a microscope and want a tardigrade you can follow these steps:

  1. Use a knife to scrape off some moss into a petri dish.
  2. Turn over the moss and soak it in water for a day.
  3. Take out any big chunks of moss or dirt and put the petri dish under a microscope. (One time I could see green chlorophyll in its belly)
  4. If you see one in the microscope, water the moss like a plant, after all, tardigrades only need water and moss to survive.
  5. If you don’t get a tardigrade, you can retry the steps again or order a tardigrade online.

Then you have your pet!

*An extremophile is a microorganism, especially an Archean, that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.