Precession of equinoxes
Standish, E. Myles Formerly, Jet Propulsion Laboratory, National Aeronautics and Space Administration, Pasadena, California.
Harrington, Robert S. Formerly, U.S. Naval Observatory, Washington, DC.
Last reviewed:December 2019
- Earth's axis
- Earth's orbit
- Related Primary Literature
- Additional Reading
A slow change in the direction of the axis of rotation of the Earth and also a very small change in the orientation of the Earth's orbit around the Sun. Thus, both the celestial equator (the projection of the terrestrial equator onto the sky) and the ecliptic (the projection of the Earth's orbit onto the sky) move slowly in time, and, consequently, so do their intersections, the vernal and autumnal equinoxes. See also: Celestial sphere; Ecliptic; Equator; Equinox
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 45 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information