Cosmic radiation might not sound like a good source of preserving life. But that is exactly what a paper recently published in the Journal of the Royal Society Interface attempts to explain.
The researchers looked at an enigmatic microbe called Desulforudis audaxviator that lives 2.8 kilometres (1.7 miles) below the surface in a gold mine in South Africa.
It manages to live though there’s no oxygen, no carbon and no light.
Researchers believe that this rod-shaped bacterium gets its energy from radioactive uranium. An article in Science gives the details:
“It draws its energy from the radioactivity of uranium in the rock in the mine. The radiation from decaying uranium nuclei breaks apart sulfur and water molecules in the stone, producing molecular fragments such as sulfate and hydrogen peroxide that are excited with internal energy. The microbe then takes in these molecules, siphons off their energy, and spits them back out. Most of the energy produced from this process powers the bacterium’s reproduction and internal processes, but a portion of it also goes to repairing damage from the radiation.”
The discovery spurred researchers to speculate that there might be life elsewhere in the universe that likewise thrives in harsh environments, not getting their energy directly from photosynthesis or living on plants that do so, but directly from radioactive uranium or cosmic rays.
Even the tiniest bacterium is by no means simple. It is full of tiny machines that are so intricate that their inventor should receive a Nobel Prize, as the best humans can do pales in comparison to what they do.