Tardigrades are tiny organisms, living right now in your backyard, that can survive the vacuum of space, and whose ancestors might have been brought to Earth on the back of a meteor. There are many hundreds of species of tardigrade on the planet, found in every possible environment. Observing tardigrades is like having a true close encounter of the third kind. These tiny creatures are easy to collect, can be studied with even the most inexpensive microscopes, and can be used for any number of science projects for kids.
Tardigrades: These adorable animals are microscopic, eight-legged critters that are content
- being boiled in hot water
- drying out like a raisin for up to a decade
- freezing to near absolute zero
- at pressures as high as those near the ocean floor
- at pressure as low as the vacuum of space
- in radiation 1,000 times higher than what most animals can survive
- on trees in your backyard
How Can You Have A Sighting?
- Collect a tiny chunk of moss, a lichen or two, or a pinch of soft bark.
- Put your sample in a Petri dish or make a clear dish using a: container lid, CD case, bit of hard plastic packaging, painting or crafting trays or containers.
- Top off the sample with purified (spring, de-ionized) bottled drinking water.
- Let the sample soak for several hours or overnight.
- Put your dish under a microscope (even a dissecting scope or low-powered “toy” microscope will work).
- Move the sample around looking for little bear-like creatures. Use a picture for reference.
Once You’ve Abducted One, What Experiments Can You Perform?
- You’ll see now that these little fellas are clear. You can watch their hearts beat. Count and compare the average number of beats per minute when you put the tardigrades under various stressors such as: poking them, chilling the sample in the fridge, or placing a few drops of a harsh chemical near them.
- Test the tardigrade’s survival skills yourself. Count the number of tardigrades per microscope view in several spots in the dish. Take an average to come up with a good estimate of how many creatures are in the sample dish. Then freeze the sample, boil it, or allow it to dry out over several days or a week. Examine the dish again and recount, only counting tardigrades that are still alive.
- This book by Michael W. Shaw is a fantastic resource for a kid who really wants to venture deeper into this extreme world. In it you will find many more project ideas and more detail about how to successfully collect good samples for observation.
Are Tardigrades Really Aliens?
Tardigrades are extremophiles – organisms that live in (even enjoy) the most extreme, harsh, ridiculous conditions planet Earth can provide. We have no way of knowing if tardigrades, or other extremophilic organisms, actually share a common ancestor with an organism planted on Earth long ago by a meteor or comet. But, it is possible.
Exobiologists are scientists who study alien life. Of course, they don’t have any actual, confirmed extraterrestrial life to work with. However, extremophiles such as tardigrades give them a good model for what organisms would be like who live on other planets with different conditions than those here on Earth. What would their bodies look like? How would their biological processes and biochemistry differ from ours?
Tardigrades can repair their busted DNA with higher speed and greater efficiency than most other common critters. They have sugars in their bodies that don’t break down as fast as the sugars other animals use for metabolic (energy-producing) processes. Because of that, they can remain dried out as little crusty globs of body parts and sugar for up to ten years. Studying how tardigrades can accomplish such amazing feats of survival gives scientists a clue as to how organisms could live on an asteroid, Mars, one of Jupiter’s moons… anywhere that has an environment outside the comfort zone of most Earth-based creatures.