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Sun May 30, 2021, 03:23 PM

Earth's Underground Worlds May Run on Radioactive Decay (Atlantic)

Jordana Cepelewicz and Quanta Magazine
May 29, 2021

Scientists poke and prod at the fringes of habitability in pursuit of life’s limits. To that end, they have tunneled kilometers below Earth’s surface, drilling outward from the bottom of mine shafts and sinking boreholes deep into ocean sediments. To their surprise, “life was everywhere that we looked,” says Tori Hoehler, a chemist and astrobiologist at NASA’s Ames Research Center. And it was present in staggering quantities: By various estimates, the inhabited subsurface realm has twice the volume of the oceans and holds on the order of 10^30 cells, making it one of the biggest habitats on the planet, as well as one of the oldest and most diverse.

Researchers are still trying to understand how most of the life down there survives. Sunlight for photosynthesis cannot reach such depths, and the meager amount of organic carbon food that does is often quickly exhausted. Unlike communities of organisms that dwell near hydrothermal vents on the seafloor or within continental regions warmed by volcanic activity, ecosystems here generally can’t rely on the high-temperature processes that support some subsurface life independent of photosynthesis; these microbes must hang on in deep cold and darkness.

Two papers published in February by different research groups seem to have solved some of this mystery for cells beneath the continents and in deep marine sediments. They show evidence that, much as the sun’s nuclear-fusion reactions provide energy to the surface world, a different kind of nuclear process—radioactive decay—can sustain life deep below the surface. Radiation from unstable atoms in rocks can split water molecules into hydrogen and chemically reactive peroxides and radicals; some cells can use the hydrogen as fuel directly, while the remaining products turn minerals and other surrounding compounds into additional energy sources.

Although these radiolytic reactions yield energy far more slowly than the sun and underground thermal processes, the researchers have shown that they are fast enough to be key drivers of microbial activity in a broad range of settings—and that they are responsible for a diverse pool of organic molecules and other chemicals important to life. According to Jack Mustard, a planetary geologist at Brown University who was not involved in the new work, the radiolysis explanation has “opened up whole new vistas” into what life could look like, how it might have emerged on an early Earth, and where else in the universe it might one day be found.
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more: https://www.theatlantic.com/science/archive/2021/05/radioactive-decay-underground-worlds/619030/

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Reply Earth's Underground Worlds May Run on Radioactive Decay (Atlantic) (Original post)
eppur_se_muova May 30 OP
Xipe Totec May 30 #1
ms liberty May 30 #4
OhZone May 30 #2
Sneederbunk May 30 #3
NNadir May 31 #5

Response to eppur_se_muova (Original post)

Sun May 30, 2021, 03:33 PM

1. It's reassuring to know that life will re-emerge, if we off ourselves in WWIII

We might even provide the fuel needed to accelerate the process.

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Response to Xipe Totec (Reply #1)

Sun May 30, 2021, 03:56 PM

4. I like to tell it this way: you can call me a treehugger, but the trees will be fine

And the planet will be fine, once we humans are extinct and enough time has passed for the planet to recover.

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Response to eppur_se_muova (Original post)

Sun May 30, 2021, 03:40 PM

2. So the reboot of godzilla -

making him an ancient creature who ate radioactivity might be that implausible?

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Response to eppur_se_muova (Original post)

Sun May 30, 2021, 03:49 PM

3. Where does DU keep its radioactive decay?

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Response to Sneederbunk (Reply #3)

Mon May 31, 2021, 09:28 AM

5. With me, I think. n/t.

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