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Where did our Moon come from?

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NASA

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Well, actually, there have been several theories over many decades.

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Earlier versions of lunar formation theories included capture,

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where the Moon would have been a strayed planetoid.

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Another version was fission, where the Earth was spinning

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so fast that it would have blorped out
of the Earth and then formed its own body.

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This led to our current theory, the giant impactor theory.

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So this collision was during the late
stages of planetary formation

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throughout our entire solar system,
when planets were still very new and very much forming.

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So this happened when Earth was just an embryo —

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a baby planet, and this was actually in a crash course

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collision with Theia, which is a Mars-size planetoid.

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And this collision ripped apart early Earth's crust.

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And that crust then coalesced. It snowballed

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into a whole separate entity, which we now call the Moon.

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So where did our Moon come from?

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Well, currently, our understanding is that the Earth

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had collided with a Mars-sized object named Theia.

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But once we send future astronauts to the lunar surface again, who knows?

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We may actually have a whole new theory in the coming decades.