What is the difference between the precession of earth's orbit and the obliquity of earth's orbit?

1 Answer
Jun 30, 2016

Obliquity is the constant inclination #23.4^o# of Earth's polar axis with the normal to the ecliptic and precession is the revolution of this axis about the normal in 258 centuries, nearly..


The Earth's axis about which we revolve every 24 hours is inclined

to the normal to the Earth's orbital plane (ecliptic), at #23.4^o#,

nearly. This is called obliquity.

Nodding gently about the center of the Earth, this axis revolves

about this normal, in a period of Great Year = 258 centuries, nearly.

The gentle nodding called nutation is multi-periodic and is

compounded with verily slow revolution about the normal to the

ecliptic called precession.