Is it in any way possible for the moon of a given planet to vanish permanently? Like, for instance, a meteor coming out of somewhere, colliding with a planet's moon, thereby crushing it. I'm curious if such a thing is possible for my own world, where allegedly, there had been a moon for a time, but some event resulted in its disappearance.
Disappear without a trace? Not really - at least, not if you want to keep with science-as-we-know-it.
However, if you want to make a moon go away, you can always smash a large rock into it. That happens all the time in the universe, and it can be spectacular.
To remove a moon from a planet, you’d have to hit it with something big enough to either knock it out of orbit or completely destroy it. Neither of these would be easy to do.
If your moon is very large - let’s take Earth’s Moon as an example - making it go away is going to be difficult if you want to keep the planet it orbits inhabited. You’d have to hit it with something approaching the size of the Moon itself. The probable result is that the Moon, and the impacting body, would completely shatter. Much of the pieces left would fall onto Earth, and we all know what would happen afterwards. Hint - you don’t want to be on the planet when it happens (unless you’re a Thundarr fan like I am).
However, there is an event that could yank a moon - even a large moon - out of a planet’s orbit without doing too much damage to the planet. Let’s again take Earth and her Moon as an example.
Imagine if a large, dense body - like a large planetoid the size of Mars - sped by the Earth very close to the Moon. It’s gravity could pull the Moon out of Earth’s orbit without hurting Earth too much (although there might be a number of earthquakes and volcano eruptions during that time).Chances are the Moon wouldn’t stay with the planet that pulled it away from Earth. instead, the Moon would probably take up an orbit around the Sun and become a new, but small, planet.
I’m not saying that this would be a common occurrence, but it is plausible.
Something like this might have already happened to the Earth, knocking the Moon into a tilted orbit.
It’s easy to imagine a planet with an Moon-sized moon being ripped from orbit by a wandering body. The people alive then would have seen the intruding planetoid and watched as their moon was pulled away. All while this was happening, there would be powerful earthquakes, volcanoes, and larger than normal tides.I wouldn’t doubt that the people on that planet would pass down some powerful end-of-the-world myths, or stories about how ‘people were evil, so God sent a demon that stole the moon.’
Yeah, I’d be scared of that story.
