Celestial Paths of the Moon and Sun

Celestial Paths of the Moon and Sun

. The Moon's orbit is titled 5 degrees to the Sun's route across the sky, the ecliptic, allowing these paths to cross at two nodes. These are the only points at which eclipses can occur. During a lunar eclipse the Moon and Sun are located at opposing nodes, so that the Moon can move into the Earth's shadow cast by the Sun. A solar eclipse occurs when the Moon and Sun cross paths at the same node.

Copyright 2010, Professor Kenneth R. Lang, Tufts University