Episode 5 of our space show, Spaced Out. See other episodes in the video room
Mike Shaw is a quiet, unassuming man in love with the wilderness. He also knows a lot more about tardigrades than your average human. These microscopic creatures, whose name comes from the German for “slow walker,” and who are sometimes called “water bears,” after their bear-like gait, are biological oddities. While their nervous system looks and acts like us, they are wholly different and can survive in extreme situations that almost no other living organism can – including space.
Beginning in 2007, biologists sent these little suckers up to the space station (along with other so-called extremophiles) and found that tardigrades can survive the vacuum of space and the life-zapping radiation of the sun. Other experiments have shown that adult tardigrades can survive both extreme pressures and temperatures, ranging from -459 degrees Fahrenheit (-273 Celsius) up to 300 degrees Fahrenheit (149 Celsius). Even if recent DNA and RNA sequencing show that tardigrades are the sister group to arthropods and Onychophora, their evolutionary lineage is unclear. Some have even theorized – cue the X Files music – that tardigrades came from another planet, and rode to Earth on space debris.
Their secret? The little water bear is one of few groups of species that are capable of reversibly suspending their metabolism and going into a dehydrated state called cryptobiosis. In this kind of suspended animation, a tardigrade’s metabolism lowers to less than 0.01% of normal, with water content dropping to 1% of normal. No wonder they’ve got staying power: some 1,150 species of tardigrades have been described throughout the world, and they’ve been found to live virtually everywhere, from the Himalayas (above 20,000 feet), to the deep sea (below 13,000 feet) and from the polar regions to the equator.
The amazing tardigrade, also known as the water bear
But back to Mike. He decided that we as a human race needed to know more about these otherworldly creatures. He set out to do a field study of the tardigrade population of New Jersey. (You can find them in lichens and mosses, on dunes, beaches, soil, and marine or freshwater sediments.) He studied these moss piglets over a year and half and submitted a paper to a renowned tardigradoligist (yes, that’s a real kind of scientist). His research is done, and while he waits for the paper to see the light of day, he has since moved on to Virginia. But he hasn’t changed his routine. Being quiet in the woods with no focus other then to look and interact with these microscopic animals has changed him. And even if he doesn’t really know if these mysterious little creatures came from outer space, he says he’s more at peace now. After having spent some time with Mike and these little space bears in the woods, so are we.
A “space bear” (not, technically, a tardigrade)
The previous episode of Spaced Out: how NASA used a sealab in Florida to practice how to save the world. Also see our documentary on the end of America’s biggest gadget and the hacker who brought the Internet to Occupy Wall Street.
Photos by Derek Mead