Could a loss of rotation in the earths core cause the moon to break its orbit?

Question

Say the earths core starts to slow down and come to a stop. I heard that its possible this can far in the future happen. If it does indeed happen, could the lack of an active core cause changes in gravity, or in some other way react negatively towards the moons orbit causing it to either crash down on us or float free?

Answer 1

The moon's orbit is mainly set by Earth's *mass.* If Earth's core were to freeze in place Earth's mass would remain the same. The main thing that would happen with an inert core is most of Earth's magnetic field would disappear, which in turn would allow lethal high-energy particles from the sun to bombard the surface.

Answer 2

No.Because of two things:

1. Moons orbit is mostly sustained by the moon itself - as long as it does not slow down or speed up, it will not leave it.It currently moves away from Earth by about 2 cm per year, later this movement might change - very far in the future.

Earths rotation is stabilized by the moon because of tidal lock, in the long term, Earth will rotate as fast as one moon orbit takes. This exchange of momentum is the reason why moon is moving away. moon slows Earth down, but the tides in Earths oceans reduce the effect. by the conservation of impulse, moon has to speed up when it slows Earth down, speeding up makes the moon move away from Earth.

2. Let's assume, the recent evidence of Earths core rotating faster as the rest of Earth is correct and it rotates 0.3-0.5° per year faster as the rest of Earth. That, it has a huge amount of momentum, which makes it impossible to quickly stop it, let alone change the rotation axis a bit. But it could also be slower by the same amount, or as fast as the rest of Earth.

When the rotation speed of earth slows down, it will be possible that Earths magnetic field gets weaker, but it will not make the moon crash on Earth.

Answer 3

I would like to add that by the time the earths core experiences a loss of rotation, due to tidal forces, the moon will be much further away from earth then it is today. In fact the earth will be tidaly locked with the moon so the same side of earth always faces the moon, while the other side never sees it. There will be no more total solor eclipses in 500 million years or so. By that time, the sun will have also increased in birghtness and the earth will only be able to support human life near the poles. And in 1-2 billions years or so the earth wont be able to support any known form of life at all. Including thermophylic bacteria.