Question

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

Answer 1

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..

Explanation:

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.