New York Times:

Some 200 to 600 octillion microbes live beneath our continents, suggests an analysis of data from sites all over the world, and even more live beneath the seafloor. Together they weigh the equivalent of up to 200 million blue whales — and far more than all 7.5 billion humans. Subterranean diversity rivals that of the surface, with most underground organisms yet to be discovered or characterized.

As scientists continue their studies, the organisms they find are challenging and expanding the tree of life.

I remember as a kid learning about all the “cooties” that live in our body and being really creeped out about it. I’m not creeped out by the thought of octillions of creatures living beneath our feet but it’s equally as amazing.