Tardigrades are microscopic animals, which are among the few lifeforms on Earth capable of surviving the intense radiation, temperature extremes and complete vacuum of outer space. Their eggs can also survive the depths of space, possibly hatching on other planets after having traveled interstellar distances.
Astrobiologists published their findings on April 10th in the journal Astrobiology.
Tardigrades are also known as water bears, and thrive in wet conditions. They eat algae, bacteria or single-celled animals. When their puddles dry up, they enter a state of total metabolic shutdown, known as anhydrobiosis. They can remain like this for over 10 years, and get back to life when it becomes wet again.
Tardigrades have already shown that they can survive exposure to space and they’re also able to survive in absolute zero, heat exceeding 300˚F, pressures dozens of times greater than at the bottom of the Marianas Trench as well as intense blasts of radiation.
Astrobiologists were curious to find out how tardigrade eggs would fare in similar conditions. They put Ramazzottius varieornatus, a species of tardigrade, under extreme stresses. The eggs were capable of surviving low temperatures, -320˚F and as high as 122˚F. Eggs were capable of surviving the exposure to space and 1,690 Grays of radiation. Humans die in days when exposed to 1% of that dose.
Reference: “Tolerance of Anhydrobiotic Eggs of the Tardigrade Ramazzottius varieornatus to Extreme Environments” by Daiki D. Horikawa, Ayami Yamaguchi, Tetsuya Sakashita, Daisuke Tanaka, Nobuyuki Hamada, Fumiko Yukuhiro, Hirokazu Kuwahara, Takekazu Kunieda, Masahiko Watanabe, Yuichi Nakahara, Seiichi Wada, Tomoo Funayama, Chihiro Katagiri, Seigo Higashi, Shin-Ichi Yokobori, Mikinori Kuwabara, Lynn J. Rothschild, Takashi Okuda, Hirofumi Hashimoto and Yasuhiko Kobayashi, 20 April 2012, Astrobiology.