Professor and geoscientist Tullis Onstott recently published an article in Nature outlining a remarkable discovery: microscopic roundworms know as nematodes living nearly two-and-a-half miles between the Earth’s surface in South African gold mines. Nematodes usually live within 20 feet of the surface. No one believed they would be found so far down.
The discovery has raised questions about whether even more complex organisms are living deep beneath the earth’s surface. The recent discovery of the worm extremophiles – a word used normally to describe microbial life found in habitats previously thought uninhabitable – is remarkable not only for the depth at which it was found, but also for its biological complexity. A wide range of single-celled life has been known for a while to survive at great depths. Scientists had assumed that the constraints of temperature, energy oxygen, and available space would make it impossible for larger creatures to exist. Yet these worms, a half-millimeter long, can apparently tolerate the extreme conditions. Thus the nickname, “worms from hell.”
The discovery also provides hope that some forms of life may be living under the surface of Mars. “Everything is frozen on the Martian surface, but you down a half-kilometer or so and things get warmer,” said Onstott. “Also, you have caves on Mars where water might have risen through evaporation, frozen, and crystallized. That’s where you want to go looking for life on Mars.”