For a story that I'm writing, I would like to know what would happen to the Earth if a meteorite bigger than the Moon (a planetoid, then) came very close to the Earth (as close as the Moon). I guess the tides would get all messed up, probably creating tsunamis and such, but I'm sure there would also be something else. Would it disturb the volcanic activity of the Earth, creating earthquakes ? Would it move the Earth out of its orbit ? What would happen to the Moon ? If the planetoid came by very quickly, is it possible that the Moon would start orbiting around it, or at least, move from its own orbit ?
(in the rest of the story, the planetoid collides with the Moon)
When the collision happens, it will probably generate a lot of heat., Something like 4000 celsius degrees or even more. This is happening outside the Earth atmosphere, so will it have any consequences on the Earth ? Will the air get hotter ?
Now, imagining that, by chance, none of the pieces of the Moon crashes on Earth, what would happen to the tides ? To tidal forces ? Which consequences will the absence of the Moon have on the ocean and on the Earth ?
Second case, the Moon explodes. This explosion will certainly not happen in two or three seconds, it will be much longer. During and after the explosion phase, will the remains of the Moon go on on a Moon-like orbit (or close to it) ? After that, of course, many pieces will probably find another orbit around the Earth, a bit like the ring around Saturn. If a very big piece was bound to crash on the Earth, I guess it would take at least twenty hours or more before it enters the Earth atmosphere (and then, it would happen very quickly). 380'000 km to go, that's quite a long way, no ? So, even if the pieces of the Moon have the same speed or a bit less than the planetoid which collided with the Moon, it wouldn't happen all at once, am I right ?
Sorry, that's several very difficult questions, I'm really aware of that... So, it's there's a physicist or an astronome here, I would be glad for a bit of help !!! Thanks a lot !!!