
Originally Posted by
Ken G
You certainly do need to explain more, especially the part where you actually need to be correct, which you aren't. If all we have is idealized gravity from the Earth and the Sun in this problem, and go into a co-orbiting reference frame so that the Earth is stationary, then what the coriolis force will actually do is cause the Moon's orbital plane to precess about the vertical, but its tilt will not change at all. Indeed, in the regular reference frame where the Earth is going around the Sun, the Moon's orbital plane wouldn't change at all, so when you go into the orbiting reference frame, it has to go around a little circle in one year. That's all the coriolis force does. If you doubt it, you need to actually do the calculation, not argue what will happen based on oversimplified equations that don't even apply in the situation at hand (granted, I'm not even doing that, I'm just "asserting" the solution, but I am also not claiming a new and bizarre explanation for why the Moon's orbit is in the ecliptic plane).