Why is the orbit of Earth's moon so anomalous?

kevinatilusa

Anomalous in what sense? The most "surprising" thing about the orbit (from my perspective, at least) is that it just happens to be so perfectly timed with the Earth's Orbit that it always ends up showing the same face towards the Earth. This isn't random chance so much as a system approaching its equilibrium. Right now the Earth rotates quickly enough that it doesn't always show the same face towards the moon. However, the tidal force of the moon acts to slow the Earth's rotation by a very small amount (~1.5 seconds per 100,000 years), and will continue to do so until the Earth always shows the same face towards the moon. As I understand it, because the Earth is so much more massive than the moon, the Earth completed adjusting the moon's orbit much more quickly than the other way around, so the Moon is already showing the same face all the time. Mar 22 04, 11:30 PM

lothruin

It's really more of a timing between the moon's rotation and it's orbit around the Earth, rather than with Earth's orbit. Probably what you meant, but we ought to be clear. Mar 23 04, 2:48 PM