When you think of life on Earth, you picture people, birds, fish, bugs, wild animals, and more. You may even think about things like worms, grubs, and other creatures that live just under the surface of the ground. What you likely don’t think about, however, are tiny living things miles below the surface.

The environment so far below the surface is extremely hostile with high temperatures, incredible pressure, very little nutrients, and of course, no light. So, it makes sense to assume that there would be little to no life down at these depths. That is even what most scientists assumed for most of history.

As more and more data is becoming available, however, it appears that this is not just wrong, but WAY wrong.

In fact, it is estimated that as much as 70% of the microbes on the planet live underground. These microbes are mostly bacteria, archaea, and eukarya that live at these depths, though there are also nematodes proven to live 1.4 km (.8 miles) down in a gold mine in South Africa.

In a statement made in 2018 by Karen Lloyd, an Associate Professor of Microbiology at the University of Tennessee it was said:

“Ten years ago, we had sampled only a few sites – the kinds of places we’d expect to find life. Thanks to ultra-deep sampling, we know we can find them pretty much everywhere, albeit the sampling has obviously reached only an infinitesimally tiny part of the deep biosphere.”

Since then, researchers have worked with drilling companies, scientists, and others to gain access to samples brought up from anywhere between 2.5 and 5 kilometers (1.1 -3.1 miles) below the surface. These samples were pulled up from all different regions of the planet including both below the ocean floor and under dry land. In all the cases, the researchers were able to find various microbes living their life.

As more samples are brought up, researchers will be able to learn more about what types of microbes are living in what parts of the world below the surface. It is not known whether there will be different microbes in different regions like there are up on land, or if it will be the same ones throughout this part of the planet.

Some researchers are also curious as to what, if any, impact these microbes have on life up here on the surface. This is one area where a lot more study is certainly needed.

If you thought that was interesting, you might like to read about 50 amazing finds on Google Earth.