Precession Of The Equinoxes

Definition: Precession Of The Equinoxes

1. A slow westward shift of the equinoxes along the plane of the ecliptic caused by precession of the Earth's axis of rotation.

Specialty Definition: Precession Of The Equinoxes

Domain	Definition
Aerospace	The conical motion of the earth's axis about the normal to the plane of the ecliptic, caused by the attractive force of the sun, moon, and other planets on the equatorial protuberance of the earth.The effect of the sun and moon, called lunisolar precession, is to produce a westward motion of the equinoxes along the ecliptic. The effect of other planets, called planetary precession, tends to produce a much smaller motion eastward along the ecliptic. The resultant motion, called general precession, is westward along the ecliptic at the rate of about 50.3 seconds of arc per year. The component of general precession along the celestial equator, called precession in right ascension, is about 46.1 seconds of arc per year; and the component along a celestial meridian, called precession in declination, is about 20.0 seconds of arc per year. (references)
Space	A slow motion of the axis of the Earth around a cone, one cycle in about 26000 years. As a result, the celestial pole moves around a circle in the sky, and in ancient times, for instance, was quite far from Polaris. Discovered by Hipparchus around 130 BC as a slow shift of the vernal equinox around the ecliptic (i.e. around the zodiac). (references)
Source: compiled by the editor from various references; see credits.

Specialty definitions using "precession of the equinoxes": Milankovich theory. (references)

Alternative Orthography: Precession Of The Equinoxes

Hexadecimal (or equivalents, 770AD-1900s) (references)

Leonardo da Vinci (1452-1519; backwards) (references)

Binary Code (1918-1938, probably earlier) (references)

HTML Code (1990) (references)

ISO 10646 (1991-1993) (references)

Encryption (beginner's substitution cypher): (references)