Classical Moon origin hypotheses

Classical Moon origin hypotheses

Fig. 5.32 . According to the fission hypothesis (left), the rotational speed of the young Earth was great enough for its equatorial bulge to separate from the Earth and become the Moon. In the capture hypothesis (middle), a vagabond moon-sized object once passed close enough to be captured by the Earth's gravitational embrace. We have pictured disruptive capture, with subsequent accretion, but the Moon might have been captured intact. The accretion hypothesis (right) asserts that the Moon formed from a disk near the young Earth.

Copyright 2010, Professor Kenneth R. Lang, Tufts University