Tardigrades (commonly known as water bears or moss piglets) may reach a length of 1.5 millimetres. The name water bear comes from the way they walk, reminiscent of a bear’s gait. They can be found across the world, from the highest peaks to the deepest oceans, and scientists now think they may even be able to survive interplanetary space travel:
Researchers in 2007 launched anhydrobiotic adults into orbit above Earth to see if they would survive. Those animals endured naked exposure to space for 10 days, and a few even made it through an excessive dose of ultraviolet radiation while back on Earth.
Other laboratory experiments show that adult tardigrades can survive cold near absolute zero (-459 degrees Fahrenheit), heat exceeding 300 degrees Fahrenheit, pressures dozens of times greater than at the bottom of the Marianas Trench, and intense blasts of radiation.
But what of tardigrade eggs? Some flew on the 2007 mission, but they weren’t exposed to the extreme temperatures and radiation found outside Earth’s protective magnetic shield.
To learn how the eggs would fare, NASA and astrobiologists in Japan devised three extreme stress tests for the eggs of a tardigrade species called Ramazzottius varieornatus.
In one set of tests, more than 70 percent of anhydrobiotic eggs survived temperatures as low as -320 degrees Fahrenheit and as high as 122 degrees Fahrenheit. Eggs exposed to vacuum-like conditions hatched just as well as normal eggs. Finally, more than half of anhydrobiotic eggs endured 1,690 Grays of radiation. A human would die in days if exposed to one percent of that dose.
- Tardigrade Eggs Might Survive Interplanetary Trip – wired.com
- New study is a further testament to the hardiness of the water bear – sciencecenter.tumblr.com
- Water bear in moss – sciencephoto.com
- Tiny Puddle-Dwelling Beasties and Their Eggs Might Survive Interplanetary Travel – blogs.discovermagazine.com