Odd Species Feeds on Nuclear Energy from Natural Uranium: Alien-like Life on Earth

Life on Earth has been known to take so many forms, uptake food for energy in so many ways, and adapt so well it seems like compelling evidence on its own that life exists all around the universe.

Bacteria are known to withstand extreme conditions no other life-forms (except maybe viruses?) could. For example, we recently reported on bacteria that survives in volcanic mud as acidic as lemons, and uses rare earth metals such as cerium and lanthanum to survive.

A similarly unusual bacteria called Desulforudis audaxviator made headlines recently, for a study that observes its ability to feed on chemicals created from nuclear energy emanating from nearby uranium. Its home can be found about 1.86 miles underneath the ground.

In total darkness, in hot groundwater up to 140 degrees Fahrenheit or 60 degrees Celsius this creature survives without organic compounds most bacteria need, without oxygen, sunlight, or anything. What it does have, is uranium.

Desulforudis audaxviator was discovered in 2008, the only bacteria found in groundwater from the Mponeng gold mine in South Africa. It is believed that it had lived there for millions of years. Completely alone in the deep underground darkness, the bacteria doesn’t even feed on any other species.

The extremely deep subterranean mine reportedly features water leaking through the cracks, and the water is filled with radioactive uranium. Free radicals are produced in the process in which uranium breaks down the water molecules, and then the free radicals break down the nearby rocks.

When the free radicals produced by uranium breaking down water break down pyrite for example, sulfate is produced. Sulfate is what these bacteria feed upon. With the sulfate produced, the bacteria are able to synthesize ATP (adenosine triphosphate), the main nucleotide that functions to store energy in cells across all walks of life. That is slightly less exciting than a bacteria directly feeding on uranium, but nevertheless it is interesting.

Published in the journal Nature with the title “Microbial habitability of Europa sustained by radioactive sources,” a major angle of the recent study on Desulforudis audaxviator is the fact that they say the existence of this bacteria could imply that similiar bacteria could exist on Jupiter’s Moon Europa.

Researchers from the University of São Paulo and the Brazilian Synchrotron Light Laboratory claim that this bacteria is perfect for assessing the probability of extraterrestrial life being out there.

Principal investigator Douglas Galante said to FAPESP, a Brazilian news outlet:

“We studied the possible effects of a biologically usable energy source on Europa based on information obtained from an analogous environment on Earth.”

“This is the first time an ecosystem has been found to survive directly on the basis of nuclear energy.”

The reason is, NASA believes that Europa might have hydrothermal vents, similiar to Earth. That is, heat gushing holes in the seafloor, where life can survive with heat and not necessarily sunlight.

“The ocean bed on Europa appears to offer very similar conditions to those that existed on primitive Earth during its first billion years. So studying Europa today is to some extent like looking back at our own planet in the past,” Galante added.

“In addition to the intrinsic interest of Europa’s habitability and the existence of biological activity there, the study is also a gateway to understanding the origin and evolution of life in the Universe.”

However, NASA’s history should be recognized when people consider every claim they make. Evidence that we can tangibly prove would be nice.

According to Science Alert:

“In their paper, the team determined that the conditions under which Desulforudis audaxviator has thrived for so long are also plausible on Europa.

There are three ingredients required to make Europa habitable, according to NASA. Water, which seems likely based on observations and models of the moon; heat; and the chemicals needed to feed the life.

Although it is far from the Sun, it is quite possible that there is heat in the Europan oceans. This is because its orbit around Jupiter is elliptical, which means the tidal forces acting upon it are stronger at certain points in the orbit.

Europa deforms when it’s at those points, which creates internal friction, generating heat in turn.”

“Their presence had been detected and measured on Earth, in the meteorites that come to Earth, and on Mars. So we can say with some certainty that this must have occurred on Europa as well,” Galante continued.

“In our study, we worked with three radioactive elements: uranium, thorium and potassium, the most abundant in the terrestrial context. Based on the percentages found on Earth, in meteorites and on Mars, we can predict the amounts that probably exist on Europa.”

This is closer to the kind of science people can universally respect: learning about the lifeforms of our planet, learning about the world and universe we live in, out of an innate curiosity about our existence.