There’s Life 3 Miles Under Earth’s Surface, More Than There Is Above It, Scientists Discover

December 18, 2018 at 5:29 pm

Advancements in deep drilling technology  have revealed a “subterranean Galapagos” miles beneath our feet

Scientists have drilled a record 5 kilometers into the earth, at hundreds of sites around the globe, to see what kind of living organisms they could find, if any.

What they found was an entire new biosphere, twice the size of the ocean. The carbon mass of the organisms there is up to 385 times the carbon mass of all the humans on Earth.

After 10 years of study, the international research group Deep Carbon Observatory is now releasing models of the underground ecosystems they’re discovering.

It is now estimated a whopping 70% of Earth’s organisms live deep under its surface, with millions of distinct types yet to be discovered and categorized.

The subsurface realm hosts a range of hidden habitats, including mines and deep aquifer systems in the continental zone, and sediment and igneous rock in the marine zone.

Showcasing a genetic diversity that meets or exceeds that above the surface, microbes were found from all three distinct domains in nature: bacteria, archaea (microbes with no membrane-bound nucleus), and eukarya (the domain that includes plants, fungi, and humans).

“Exploring the deep subsurface is akin to exploring the Amazon rainforest,” Mitch Sogin, co-chair of DCO’s Deep Life community.

“There is life everywhere, and everywhere there’s an awe-inspiring abundance of unexpected and unusual organisms.”

With life cycles at near geological timescales, and, in some cases, feeding off nothing more than the energy of rocks, deep earth microbes differ greatly from their surfaces cousins.

“Ten years ago, we knew far less about the physiologies of the bacteria and microbes that dominate the subsurface biosphere,” says Karen Lloyd, University of Tennessee at Knoxville.

“Today, we know that, in many places, they invest most of their energy to simply maintaining their existence and little into growth, which is a fascinating way to live.”

An unidentified nematode (eukaryote), lives 1.4 km below the surface in a Kopanang gold mine in South Africa.

Many mysteries remain for the scientists to solve:

Where do the deep-earth microbes get energy without sun or soil? How do they withstand such extreme pressure and temperatures? How do they reproduce, or live without dividing, for millions of years?

The scientists are curious whether their findings will contribute to the search for life on other planets.

In the meantime, we are left to marvel at the rock beneath our feet and all the life that teems there.

Scientists found this beneath a gold mine in South, Africa, the only deep ecosystem in the world to showcase only one species in the sample. The orange spheres are carbon, and the purple-blue rods are Candidatus Desulforudis, a bacteria that gets its energy from sulfates.