Originally posted by menace71
One of the theories is that when the earth was molten that a piece spun off of it. There are issues with this theory it seems however.
Yes -just think of the physics of it and it would appear to be quite absurd for it begs several questions:
It would have to have been spinning extremely fast! What caused it to spin so extremely fast in the first place? And if it was spinning fast enough for part of it to fling off then why didn’t that happen earlier in its history? -would that be because it spin became even faster and if so what caused this even greater increase in spin?
Also, if a mass was flung off the equator sideways by the planet’s spin, then it would either form a highly elliptical but temporary orbit where it would just go around once before crashing back into the planet (because the path of this elliptical orbit would actually touch the equator!) or it would escape the gravitational pull of the planet completely -there is no middle way where it would form a stable orbit!