"It’s like finding a whole new reservoir of life on Earth"

December 10, 2018 4:46 PM

A multidisciplinary team of scientists affiliated with the Deep Carbon Observatory are nearing the end of a decade of collaboration to explore and study life in Earth’s subsurface. After sampling microbes from hundreds of boreholes as deep as 5 km underground and 2.5 km below the seafloor, the researchers have begun reporting some of their findings [scroll down for illustrations below appendix].

With an estimated 70% of Earth's bacteria and archaea (and a lesser percentage of eukarya) living underground, the “deep biosphere” occupies a space approximately twice the volume of all the oceans and has genetic diversity comparable to life at the surface.

Some microbes in this realm may live on geologic timescales, subsisting for millions of years as “zombies” — using the limited energy available to them to repair or replace broken parts instead of dividing or reproducing.

The known limits of pressure, temperature, and energy availability under which life can endure have yet to be determined, as records continue to be broken. And there remain many questions about deep life. What are its primary sources of energy? How does it spread? And how did it get there in the first place?

posted by theory (25 comments total)

This is awesome and somehow heartening. Thank you.
posted by signal at 5:22 PM on December 10, 2018 [5 favorites]

I forgot to include this page: "Undercover Cells", which has more information and a visualization showing where (and at what depths) samples have been taken around the world.
posted by theory at 5:33 PM on December 10, 2018 [1 favorite]

And there remain many questions about deep life. What are its primary sources of energy? How does it spread? And how did it get there in the first place?

And will they remember us, in untold aeons, once they have inherited the earth from us, its unworthy stewards?
posted by Halloween Jack at 6:21 PM on December 10, 2018 [9 favorites]

Ah the meek, who shall inherit the great plastic, slime ball of death!
posted by Oyéah at 6:26 PM on December 10, 2018 [1 favorite]

That is not dead which can eternal lie.
And with strange æons even death may die.
posted by glonous keming at 6:48 PM on December 10, 2018 [6 favorites]

Not to be confused with the Dungeons and Dragons adventure Deep Carbon Observatory.
posted by justsomebodythatyouusedtoknow at 7:10 PM on December 10, 2018 [7 favorites]

When I was a kid, we were taught that the sun was foundation of the food chain for ALL life on Earth. Also, when I pointed out how closely the opposite coasts of the Atlantic Ocean seemed to echo each other, I was told it was just a coincidence.
posted by bonobothegreat at 7:26 PM on December 10, 2018 [1 favorite]

It was after we reached the 5km depth that the events began...
posted by Thorzdad at 8:14 PM on December 10, 2018 [6 favorites]

This is fascinating, and kind of brand new information to me!
posted by Secretariat at 9:16 PM on December 10, 2018 [1 favorite]

I remember years ago (like, over a decade, maybe longer?) reading about some kind of bacteria that lived in solid rock and ate rock and excreted tiny amounts of gold. Or something like that. The whole idea of deep earth bacteria has felt elusive to me for ages. I search for information and find some but not a lot.

I'm glad to see it's being researched a lot more. It's a fascinating topic. The entire non-molten planet seems to be alive.

And maybe the molten planet, too. We might just need better instruments.
posted by hippybear at 10:24 PM on December 10, 2018

Energy: Is methane, hydrogen, or natural radiation (from uranium and other elements) the most important energy source for deep life? Which sources of deep energy are most important in different settings? How do the absence of nutrients, and extreme temperatures and pressure, impact microbial distribution and diversity in the subsurface?

Since there are no new natural inputs of radioactive isotopes to the Earth aside from relatively trivial interactions with cosmic rays and particles from the Sun at the top of the atmosphere, and since amounts of radioactive isotopes go down exponentially with time, there must have been a lot more energy available from radiation when life began several billion years ago than there is now.
posted by jamjam at 10:37 PM on December 10, 2018 [1 favorite]

Energy: Is methane, hydrogen, or natural radiation (from uranium and other elements) the most important energy source for deep life?

Possibly stupid question -- how is just the heat of the interior of the Earth not a significant energy source, enough for the deep life to thrive?
posted by hippybear at 10:41 PM on December 10, 2018

gradient’s not steep enough
posted by hjo3 at 10:46 PM on December 10, 2018

I knew the Hollow Earth theory was true. Have they encountered any Hadals yet?
posted by cenoxo at 12:11 AM on December 11, 2018 [1 favorite]

“Even in dark and energetically challenging conditions, intraterrestrial ecosystems have uniquely evolved and persisted over millions of years..."

I knew the Hollow Earth theory was true.

I.T. - The Intraterrestrial
posted by otherchaz at 12:19 AM on December 11, 2018

It's the terror of knowing what this world is about.
posted by Lipstick Thespian at 1:09 AM on December 11, 2018 [1 favorite]

More life down below means an increased probability of more life out there.
posted by fearfulsymmetry at 1:35 AM on December 11, 2018 [2 favorites]

The biomass and biodiversity of the continental subsurface: a paper by Cara Magnabosco, et al.: "Based on considerations of global heat flow, surface temperature, depth and lithology, we estimated that the continental subsurface hosts 2 to 6 ×  10^29 cells and found that other variables such as total organic carbon and groundwater cellular abundances do not appear to be predictive of cell concentrations in the continental subsurface."
posted by misteraitch at 1:50 AM on December 11, 2018 [4 favorites]

At the bottom of the boreholes they will find turtles, because those go all the way down.
posted by Weftage at 6:01 AM on December 11, 2018

All the modern things
Like cars and such
Have always existed
They've just been waiting in a mountain
For the right moment
Listening to the irritating noises
Of dinosaurs and people
Dabbling outside
posted by kokaku at 6:27 AM on December 11, 2018

Surely can we make a lot of money exploiting this massive resource.
posted by waving at 6:46 AM on December 11, 2018

So...guessing all these critters excrete crude oil, right? That's their long game, man, get the surface species addicted to cheap energy to the point of self-extermination, then take over the whole biosphere.
posted by Bron at 6:48 AM on December 11, 2018

Not every planet has an ocean, and not every planet has an atmosphere, but every (solid) planet has a subsurface. This makes exobiology much more interesting.
posted by fantabulous timewaster at 6:56 AM on December 11, 2018 [3 favorites]

Though as far as extraterrestrial subsurface biomes are concerned, they do say that one of the big remaining questions is "Did life evolve on the surface and work down, or evolve down there and work up?"

If it's the latter, then exobiology becomes *very* interesting.
posted by Quindar Beep at 7:29 AM on December 11, 2018 [2 favorites]

Given how amazingly slowly the creatures down there seem to be living, it seems hard to believe they are doing much evolving, though it may be that in various pockets there are areas of higher energy where they speed up, do some evolving, and then either use up the resources or geologic forces shuffle things around so they go back to the "zombie" state.

That said, it seems like the ideal environment to breed creatures that can survive long periods of time in stasis within rocks -- ie, exactly what you need to get a lot of cross-pollination between planets, or maybe even planetary systems.
posted by chortly at 5:11 PM on December 11, 2018