Topic summary
Ecliptic plane
Extracted from the Wikipedia article Ecliptic.
The ecliptic or ecliptic plane is the apparent path of the Sun on the celestial sphere, resulting from Earth's orbit around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. The ecliptic is so named because the ancients noted that eclipses only occur when the Moon is crossing it.