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Where do moons come from?

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NASA

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Well, they actually can come from a lot of different places.

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Our Moon, for example, we believe formed in a cataclysmic impact

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between the early Earth and a Mars-sized planet. In just a few moments,

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this impact would have melted
the entire Earth into a lava world,

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sending thousands of tons of rocks
and material into space.

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Some of these rocks would combine together and form small moonlets.

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And over time, thousands of years, the moonlets would come together and form our Moon that we see today.

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On the other hand, the Galilean moons of Jupiter

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are thought to have formed from a giant disk of debris

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that Jupiter pulled in from the gas and dust that orbited the Sun

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in the early history of the solar system.

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The material in that disk would also form those same moonlets

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that eventually came together to make up
the four largest moons of Jupiter,

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IO, Europa, Ganymede and Callisto.

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For the last common way
moons are thought to originate,

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we have to look at Neptune's
largest moon, Triton.

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This moon has a very strange orbit,
which led us to hypothesize

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that it was actually a dwarf planet
from the Kuiper Belt, just like Pluto.

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One day it got too close to Neptune and was captured by Neptune's gravity.

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So where do moons come from?

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Well, we still have a lot of questions
that are unanswered,

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but with the next generation of scientists
and state-of-the-art missions,

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we hope to be able to answer the secrets
of the origins

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of the moons in our solar system.