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Game_Minds t1_j1qh57r wrote

Reply to comment by YujiroDemonBackHanma in What is the currently-accepted theory for how the moon was formed? by CopperGenie

The moon is actually really, really close in cosmic terms for a moon of its size relative to earth. Saturn and Jupiter's moons are much smaller AND much farther away. and it is in fact slowing down veeeeeeeeery marginally over time, so if the sun didn't explode eventually it might make it back to earth

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sciencedthatshit t1_j1r3hsr wrote

The moon is slowing migrating away from Earth, not towards it. And, to be pedantic, stars like the sun don't explode. They swell, puff off outer layers and then shrink into a white dwarf.

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Game_Minds t1_j1r5o47 wrote

Ahhh, okay. I remembered the 1.5 inches per year but in the wrong direction-- I think i mixed up decaying orbits / Lagrange points for closer satellites that are impacted by atmospheric friction. I had forgotten that the weird phenomena of rotation and tidal gravitational forces combine to speed up the moon's orbit, functionally the same thing as escaping. And yes, explode was a convenient fill in word for "expand into a red giant, assimilating most of the inner bodies in the solar system, then shed the outer layers in a not-quite-explosion, leaving a white dwarf core", but you're right, that's incomplete

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