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My Impacts project depicts a scene from the prolonged bombardment, a time when Earth was cratered by asteroids and comets:
That's really cool!
"Other scientists agree that some amount of water could have formed on Earth — but perhaps not nearly enough to produce its oceans." "Earth might have been a water factory for only a moment, but that moment may have been enough to forge oceans."
Well, our planet has magnetosphere and it also had life for a long time already. Although the magnetosphere reduces the influx of Hydrogen in form of solar wind proton bombardment, it also prevents the loss of Hydrogen that managed to get captured on Earth by not letting it be blown away from the upper layers of atmosphere. Life at one point, almost two and a half billion years ago, caused the Great Oxygenation Event, in which the entire atmosphere got Oxygen rich. This very special atmosphere (for all that time) made it possible for the incoming Hydrogen (be it from the Sun, other stars, or just as the most common form of dust in the universe blown in here from whatever direction and cause) to ultimately be collected as water. Two and a half billion years, that's a lot of time to accrue water. It ought to show, at some point. So it's at least one pair of factors that could have led to a surplus of water we see today, besides what might have existed from very beginning.
> Well, our planet has magnetosphere and it also had life for a long time already.
But life needed water as a requirement to arrive, right? So are you saying that there was a little bit of water for life to get started, before that same life caused the oxygenation event to create more water over millions of years?
Please explain, thank you.
Well, yes -- some amount of water must have been in there from very beginning, plus what may have fallen in as icy bodies from outer space afterwards, this much is mentioned in the article itself. The question was not if there was water, but how much of it. Most of today's planetary body of water resides in deep depressions -- seas and oceans, which is very different to what must have been initially. Back then, the surface supposedly had very little relief, due to Earth's crust being much thinner at that time. That meant that, whatever water was there, it must have been shallow, spread to very large areas.¹ This condition was especially propitious for life, as it provided ample space for life to proliferate. The first organisms must have been at the bottom of this large, never drying shallow "ocean" or mesh of (at least often) connected seas. Deep enough to shield the emerging life from UV light, but shallow enough for light to reach the developing life, including the first unicellular algae. Even today, most of life lives on the shallow waters, where plants could find minerals and underwater sunlight, and thus the whole food chain above them could be sustained.
¹ Today's amount of water spread all over an Earth with no relief gives you a kilometers-depth ocean. Even with only some modest amount of relief (as it should have been at the beginning), if it didn't reached the water surface to produce shallow waters, then that's a non-starter for life. The life should have waited a lot of time for the Earth to cool down, for the crust get ticker and thus for a more prominent relief to appear in order for it to finally get any chance to emerge. Therefore, it was very important for life to encounter an environment with just modest amount of water.
Thanks for taking the time.
Is this a chicken and egg like question?
So the theory explained here is that Hydrogen mixed with the Oxygen in the melted rock (magma) of earth, under extremely high pressure to create our earth specific flavor of H2O (appropriate amount of trace minerals and deuterium).
Am I reading that correctly?
Link to the paper mentioned in the article: https://www.nature.com/articles/s41586-025-09630-7
Correct, and we can demonstrate this via various gem-bearing and REE-bearing pegmatites which almost universally contain magmatic-sourced water trapped within them.
Could this have happened under the pressure of the interplanetary collision with the protoplanet "Theia" that led to the creation of the moon?
Wow what an awesome art piece by Ada Zejun Shen that they commissioned(?) for this article!
Their portfolio is beautiful https://adazshen.com/
Wow, what a portfolio! This one in particular caught my eye: https://adazshen.com/Viral-Placenta
I have little artistic ability myself, but I am continuously in awe of what artists create. It makes me hope for the optimistic outlook of AI where UBI frees people to pursue creative and intellectual pursuits, rather than constantly trying to push a stock price uphill.
I thought it was ai generated lol
even when websites provide attribution for images, people don't read them
Maybe some of Earth's oceans came from its rings collapsing (not kidding)
I've read Europa has more water than Earth. Is the idea that it accumulated its water through an entirely different means? Or that it formed with its water, and didn't lose it during the initial coalescence, like the Earth did?
This is one of those areas where I don't know enough to oppose the scientists that are experts in this domain, and so I know I should accept the general consensus... but there's still a niggling doubt in my mind because it just doesn't feel right.
Earth inherited water, released it, and retained it, while the atmosphere and oceans formed together as a coupled system. Heating released water via volcanism. Outgassing formed an atmosphere rich in water vapor. Cooling caused condensation and rainfall. Oceans stabilized.
Oxygen accumulated only after oceans already existed for over a billion years.
Life began in the Ocean, but why did civilization begin on land? Is it because of fire? But I wonder if a different kind of civilization could have emerged
That's one theory, yes. Cooking food (with fire) makes more calories available, meaning less hunting required to support more individuals, and/or freeing up more time and calories for thinking. This allowed us to evolve bigger and more complex brains.
While it's not a given that fire is a hard prerequisite for an industrial civilization, it certainly accelerated our technological development. Fact of the matter is, we know of exactly one civilization, which is not enough to draw any conclusions. There's no real reason we know of that aquatic species cannot evolve into a technological civilization, we just haven't seen it happen. Fact is we don't really know how an intelligent technological species evolves. We only have guesses from our own history.
Fire, agriculture, electricity, AI.
Rank these inventions in terms of importance to humanity.
That's the fun thing, since we have only observed a single advanced civilization, and that one only indirectly through archaeological evidence, there's no hard facts to be had! We can only make guesses. We don't know what is and is not required to make an advanced technological species, and we won't have any answers until we meet another one to compare with.
Arguably they're all fire -- requiring/involving forms of combustion.
(Well, debatable about agriculture, slash'n'burn wasn't the only form of it, but it was common for land clearing at least... all we have now is one that involves combustion engines, though...)
Nuclear weapons and the control structure around their use and fossil fuels and the C-corporation and what it optimizes for will probably turn out to be more important to the long-term future of humanity and it's civilization.
It looks like you've already done so with the order of the sequence that you used.
AI hasn’t taken its final form yet.
AI is not important at all. Just make things more convenient, but is completely unnecessary.
And a sample size of one.
That's what I said, yes.
Brains are resource hungry, especially oxygen hungry. Earth's air is orders of magnitude richer in oxygen molecules than its water. This likely made it easier for intelligence to develop on land. It's worth noting that the smartest aquatic animals are air breathing mammals that spent much of their evolutionary history on land before returning to water.
When did octopuses start breathing air?
Interesting to think what could be if cephalopods raised their young instead of leaving them to completely fend for themselves. It would start intergenerational knowledge transfer, i.e. culture. Maybe selection pressure then trends towards group cooperation instead of going it solo.
I still think there would be huge barriers to "civilization" as I think you mean? (Do any of the apes have "civilization"?).
The real problem with cephalopods is their lifespan. For their age, they are almost as smart as humans, the problem is that they don't live past the age of 5 years.
Orcas do this already.
I mean there might be a already a civilization that is in the building that will peak 100k years later, and we just don't know about it.
Physically manipulating objects is a lot harder underwater, even if you somehow evolve fine motor control despite not having any real use for it. So that severely limits what an intelligent aquatic species could actually do with that intelligence. Aside from fire you're missing the wheel, a writing system and many other things.
Being immersed in solvent can't help with things like graphic arts and pottery.
Humans are one of a handful species equipped to change their immediate environment to suit their needs, across virtually every environment, and introduce stability.
Beyond that…
Being able to have down time seems like a prerequisite to creating. civilization.
Also, having both the intelligence and desire to seem and recognize ways to improve—even if not strictly necessary—via tools to free up even more time also seems to be a requirement.
And having a system to reliably and in-scale transmit this knowledge is the final ingredient.
So some baseline stability, down-time, intelligence, reliable knowledge transmission, tool-use for the above, and active willingness to improve all of the above all seem like necessary ingredients.
> but why did civilization begin on land?
Octopus have civilization, despite the usual solo trip, group behavior has been observed, small neighborhoods of octopi staying within their shells and occasionally pestering each other.
Some aquatic mammals have civilization as well.
A lot of what's going on just hasn't been observed well
1) Land has more diverse and rapidly changing environments, creating generalists, creating advanced intelligence
2) Civilization requires hands, but in water fins and flippers are more useful
3) Sure, it could have worked out differently, but here we are
You're talking about a thing that happened for 1 species for such a small period of Earth's history to be just a blip. There's not enough data to draw a conclusion here.
One hypothesis is that the brain began too look (and eventually plan) farther ahead with land animals, because you have a much farther view in air than in water. On land there is more evolutionary pressure to change one’s behavior regarding animals farther away that you see and that can see you, to predict their behavior and plan one’s own behavior within a larger time horizon.
Can’t answer that, nobody will likely to be able to ever, outside religions. We are NBKs. How that happened, idk, some cosmic curse. Dolphins didn’t develop atlatals, broad heads, catapults, napalm, and F35s.
Earth made water.. right.. and a big explosion made the earth? How stupid do you think we all are?
They have played us all for absolute fools!
How could the Earth be round? All the water would fall right off!
As opposed to what, a gift from aliens?
i imagine this is what happens when a giant iceball starts to melt
200 years from now on HN.
"Where Did Earth Get Its Deserts? Maybe It's Ai, Datacentres and Climate Change"