The Plane of the Ecliptic is well illustrated in this picture from the 1994 lunar prospecting Clementine spacecraft. Clementine's star tracker camera image reveals (from right to left) the Moon [ http://lunar.arc.na…] lit by Earthshine, the Sun's corona [ http://antwrp.gsfc.…] rising over the Moon's dark limb, and the planets Saturn [ http://www.jpl.nasa…], Mars [ http://mars.jpl.nas…], and Mercury [ http://sd-www.jhuap…]. The ecliptic plane is defined as the imaginary plane containing the Earth's orbit around the Sun. In the course of a year, the Sun's apparent path [ http://www.astro.wi…] through the sky lies in this plane. The Solar System's [ http://space.jpl.na…] planetary bodies all tend to lie near this plane, since they were formed from the Sun's spinning, flattened, proto-planetary disk [ http://antwrp.gsfc.…]. The snapshot above nicely captures a momentary line-up looking out along this fundamental plane of our Solar System [ http://antwrp.gsfc.…].
