Water on Earth May Not Have Originated from an Asteroid Impact, Study Finds (discovermagazine.com)
- Reference: 0177064139
- News link: https://news.slashdot.org/story/25/04/19/0436210/water-on-earth-may-not-have-originated-from-an-asteroid-impact-study-finds
- Source link: https://www.discovermagazine.com/the-sciences/origins-of-water-on-earth-may-not-have-started-with-an-asteroid-impact
> Pinpointing when and where Earth's hydrogen is an essential key to understanding how life arose on the planet. Without hydrogen, there's no water, and without water, life can't exist here. Ironically, researchers turned to a meteorite containing hydrogen to prove that such former bodies did not provide the H2 ingredient of water's H2O recipe. They examined a rare type of meteorite — known as an enstatite chondrite — that was built similarly to early Earth 4.5 billion years ago and the team discovered hydrogen present in the chemical. The logic is that if this material resembling early Earth's composition can contain hydrogen, so too could the young planet....
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> Since the proto-Earth was made of material similar to enstatite chondrites, by the time the immature planet had grown large enough to be struck by asteroids, it would have already stashed enough hydrogen to explain Earth's present-day water supply.Although this study likely won't resolve the debate over Earth's original water source, it tilts the ta ble toward an internal, not external one. "We now think that the material that built our planet — which we can study using these rare meteorites — was far richer in hydrogen than we thought previously," James Bryson, an Oxford professor and an author of the paper, [3]said in a press release . "This finding supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed."
[1] https://www.discovermagazine.com/the-sciences/origins-of-water-on-earth-may-not-have-started-with-an-asteroid-impact
[2] https://doi.org/10.1016/j.icarus.2025.116588
[3] https://www.eurekalert.org/news-releases/1080440
Key points from the abstract (Score:1)
Due to their isotopic similarity to terrestrial rocks across a range of elements, the meteorite group that is thought to best represent Earth's building blocks is the enstatite chondrites (ECs)... Here, we explore the amount of hydrogen in ECs as well as the phase that may carry this element using sulfur X-ray absorption near edge structure (S-XANES) spectroscopy. We find that hydrogen bonded to sulfur is prevalent throughout the meteorite, with fine matrix containing on average almost 10 times more H-S tha
From whence the water? (Score:2)
For many years I have heard about the prevailing theory about how the Earth's oceans accumulated due to the impact of water-heavy comets. What I never understood was why comets would have so much water in them where the material that made up the Earth did not.
Can someone explain how the theory covers this?
Has it ever occured to anyone that God did it (Score:1)
God created everything. The entire universe.
Re: (Score:2)
My God, is the "Engineer" who found a way to use entropy, chaos, self organization, and physics, as a hammer and nails and built the universe with pure energy to matter conversion.... THAT, is my God.
Re: (Score:2)
You mean it's not the one that asks a father to murder their son and then at the last minute, after the father has committed to doing so, goes "just kidding"?
Re: (Score:1)
Nah man, we came from masturbating monkeys. I read it in a book! /s
Saturn's rings (Score:2)
It's pretty obvious looking at how much water ice is floating in space that it's a highly common resource in the early formation of planets generally. There's probably more water than rock if comets and planetary rings are any measure.
If it's buried deep inside from the outset then there's plenty to go round. I wouldn't be surprised if there is still plenty of superheated water buried deep in the Earth.
About enstatite chondrites (Score:2)
[1]https://en.wikipedia.org/wiki/... [wikipedia.org]
> Enstatite chondrites (E-type chondrites) are a rare form of meteorite, rich in the mineral enstatite.
[2]https://en.wikipedia.org/wiki/... [wikipedia.org]
> Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, (Mg,Fe)SiO3, has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20).
My thought is that it wouldn't have to actually hit "Earth" per say since at one point "Earth" was an protoplanetary disk. Basically, if lots of small enstatite chondrites impacted part of the asteroid ring, then a certain amount would statistical remain in the ring instead of passing through. It could even have impacted the outer protoplanetary disk and slowed enough to get pulled back near Earth's disk. It wouldn't need to be all at once
[1] https://en.wikipedia.org/wiki/Enstatite_chondrite
[2] https://en.wikipedia.org/wiki/Enstatite
My 2 cents on this one. (Score:3)
When viewing simulation of planetary formation, many times, there is a vast accretion disk around the planet for some time. Especially in massive body collision simulations. The one that Created the moon for example, would have left the crust molten for 50,000-200,000 years. That water would have had to have been in gas form, (an Entire Global set of Oceans worth.) for all of that time. I cannot see that much water floating around as clouds. It makes more sense that it was in the accretion disk after the initial collision, trapped by the combined gravity of both bodies unified, and eventually "Rained down" s n atmosphere formed from the remains of the accretion disk. Would have taken a few million years for that to happen. Plenty of time for the newly formed "Earth" to have solidified a surface, and cooled enough to support oceans/basins.
Re: (Score:2)
I see the model inverted. The water is deep in the centre from the outset. It takes a long time for the water to escape to the surface. Just like it takes a long time for heat to also escape.