Okay, I have no idea how true this is, but I learned in middle/high school that with each orbit the moon gets further away from the earth and in a couple million years it might get so far away that the earth won’t even have a moon anymore. Which makes me wonder… how stable is Earth’s orbit? Like what’s keeping us from getting too far away and flying off into space? Or is there a possibility of that happening ever? I’m so curious
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>with each orbit the moon gets further away from the earth
This is true. Because the Earth rotates faster than the Moon orbits the Earth, the Earth is slowly transferring its rotational energy to the Moon, causing the Earth to slow down and the Moon to orbit faster, very gradually boosting it to a higher and higher orbit.
>and in a couple million years it might get so far away that the earth won’t even have a moon anymore.
This is not true. The Earth does not have enough rotational energy to eject the Moon from orbit. As the Moon gets farther away and the Earth slows down, the rate of energy transfer will slow. Once the Earth is spinning so slowly that it matches the speed of the Moon’s orbit, the energy transfer will stop completely and the Moon will stop moving away. This process will take around fifty *billion* years, ten times longer than the Earth and Moon have existed.
The Earth and Moon have such a large “tidal” interaction because of their relative size and proximity: the Moon has about 1% of the Earth’s mass and is only about thirty Earth-diameters away. On the other hand, the Earth only has 0.0003% of the Sun’s mass and is 107 solar diameters away. The tidal forces accelerating the Earth are negligibly small, and the Sun will kill the Earth in other ways long, *long* before it has a chance to accelerate the Earth’s orbit by any significant amount.
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