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amitym t1_j20vqac wrote

Reply to comment by Karcinogene in Earth was brought to life by ancient water-rich asteroids from the outer Solar System by marketrent

Water doesn't just "boil away," though. Boiled water becomes part of the atmosphere. It's still there. Of course in the case of Mercury there is no atmosphere at all anymore. But Venus doesn't have that problem, yet it has only a small fraction of the water Earth has. Unless there's more water hidden somewhere.

Similarly, with Mars, the poles have managed to retain water ice over several billion years without all sublimating away.. so given that water is actually apparently stable on Mars over the very long term, where is the rest of it? Why aren't the polar ice sheets more extensive?

And.. I don't know about every object... the dwarf planets do not seem to be covered in water ice at all. The outer planetary moons probably didn't develop their watery crusts or interiors via asteroid impacts. Although maybe indirectly via water ice asteroid capture?

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tarrox1992 t1_j210fz5 wrote

>Pluto is about two-thirds the diameter of Earth's Moon and probably has a rocky core surrounded by a mantle of water ice. Interesting ices like methane and nitrogen frost coat the surface. Due to its lower density, Pluto's mass is about one-sixth that of Earth's Moon.

https://solarsystem.nasa.gov/planets/dwarf-planets/pluto/in-depth/

>We know very little about Eris' internal structure.

>Eris most likely has a rocky surface similar to Pluto

https://solarsystem.nasa.gov/planets/dwarf-planets/eris/in-depth/

The only dwarf planet composition that we are even slightly sure about seems to show that it is, like the other commenter said, covered in miles of ice.

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amitym t1_j211l7g wrote

Surface methane and nitrogen ice. Not water ice. Mantle of water ice is not "covered in miles of ice." It's almost the opposite. Pluto looks more like it was an ice asteroid than that it was hit by ice asteroids.

I'm not saying that ice asteroids don't exist. I'm saying that if everything in the solar system got its water from the impact of ubiquitous water ice asteroids, there should be more signs.

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Eggplantosaur t1_j23odnf wrote

Should I let the researchers know you figured it out or will you contact them yourself?

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amitym t1_j2f5vsz wrote

"Mantle" is the inside, not the outside. I wouldn't think that needs to be explained but here we are.

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