Asteroid Ryugu contains material older than the planets, among the most primitive ever studied on Earth

I am not understanding why they have decided that Ryugu must have formed "beyond the snow line" when they also say that "the samples had formed within liquid water, at a temperature of about 81 to 117 degrees Fahrenheit."

We don't seem to think that Earth had to form "beyond the snow line" in order to have water, and "81 to 117 degrees F" sure sounds like a temperature that one can find on a planet with an atmosphere at about Earth's distance from the sun.

If they think that a planet with water cannot simply condense out of the gases and dust originally in the planetary nebula, why couldn't a rocky planet that condensed inside the snow line be provided by water like they think Earth was provided by water? If the planetary nebula was so chaotic and filled with colliding protoplanets, why couldn't bodies from beyond the snow line be flung into an orbit inside that line to make a protoplanet there become wet- which then gets destroyed by another collision to make Ryugu?
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I think that what is surprising is that many of the asteroids seem to be fragments of of larger bodies, rather than small clumps of totally primordial stuff that got together without ever forming planets.

If the material found on the surface of Ryugu was formed in liquid water at the Earth-like temperatures stated, then there must have been a substantial planet involved to produce the atmosphere that can have pressure sufficient to keep water from vaporizing at those temperatures.

Too bad we didn't end up with a planet in the orbit of Mars or the asteroids that still has water and temperatures like that. Could have been "Earth 2". Or maybe life would have developed there too, and they would have been "hostile aliens" and we are better off without that?
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"There never was a good war, or a bad peace."
Unc posted:
"Or maybe life would have developed there too, and they would have been "hostile aliens" and we are better off without that?"

Yes, specially as Mars went through its cycles faster than Earth, and its inhabitants might have developed an appetite for our predecessors :screamcat:

Cat :)
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