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We are pretty sure that an impact liquified the entire surface of the Earth (creating the Moon by casting a big chunk of molten material into space). So clearly
by stallmanite 6y ago
We are pretty sure that an impact liquified the entire surface of the Earth (creating the Moon by casting a big chunk of molten material into space). So clearly the “greatest imaginable” impact does not leave the Earth more habitable than the alternatives.
- DiogenesKynikos 6y agoThat was an impact by a Mars-sized body early in the history of the solar system. That's not going to happen again. The dangers now come from objects a few kilometers across, at most.