I understand that meteor showers are due to the Earth passing through the debris left by a comet, but shouldn’t the Earth clear out any lingering meteors after a few revolutions?
In: Planetary Science
A few things. First, most orbits aren’t completely planar. Just look at our moon in that we sometimes get an eclipse during a new/full moon and sometimes we don’t. Second, the particles ejected from the comet aren’t statically floating there. Many have some momentum from when they were ejected but not enough to escape the sun’s orbit. As a result, by the time Earth revolves around the sun, it’s going through a slightly different area of the debris field and a lot of the debris that wasn’t originally in the path of Earth has moved into it.
Give it enough time, and the debris will eventually be cleared out. But time on an astronomical scale is a long, long time for humans.
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