The Tardigrades: Earth's Toughest Lifeform?

Photo courtesy of http://www.sciencephoto.com

Hank Green gives us a quick introduction to the Tardigrades, a kind of extremophile. Tardigrades, sometimes known as "Water Bears" or "Moss Piglets" live in water, have eight legs, feed on moss, and are very small - microscopic, in fact. They live worldwide in many different altitudes and environments including various levels of the ocean. They are known as very tough organisms, despite being so tiny. NASA sent these guys into space just to see if their reputations for toughness bear out. It turns out that Tardigrades are, unusually, one of the toughest organisms on Earth.

They were sent into space and tested in two controlled sets of populations. The first water bear population set was exposed to both the vacuum of space and to the solar radiation emitted by the sun. The second population set was exposed to just the vacuum of space and NOT the harmful solar radiation. Many of the Tardigrades survived the exposure and the trip back to Earth, where some of them even reproduced after their experience.

One of the implications of this experiment informs us on the possibilities of Panspermia. Panspermia is the idea that life can be seeded onto a dead world, perhaps naturally...that life is tough enough to survive a journey from one planetary body to another in a solar system. The Tardigrades's experience in space certainly opens up the possibility of a Panspermiated Solar System. if they can survive this, then what else is possible? Check out Hank Green's video below. After the video, check out some gnarly Water Bear photography #WaterBearPorn

Isn't he cute? Photo courtesy of http://www.sciencephoto.com