Physics · Observing
Nutation
Say it: noo-TAY-shun IPA: /nuˈteɪʃən/ noun
Nutation: An oscillatory change in the orientation of a rotating body's axis.
Earth's axis has smaller periodic variations superimposed on its longer-term precession. Those variations must be included when describing its orientation precisely.
- Example
- The coordinate calculation accounted for both precession and nutation.
- Why astronomers use it
- It matters when converting between accurate Earth-based and celestial reference frames.
- Tiny cosmic connection
- Nutation and precession are related orientation changes, but they are not interchangeable names for one motion.
Deep Space Physics Observing
Where to check it
Written for Cool Moon Facts in its own words; the sources cover the same idea in more depth.