2007-03-16 16:46:47 · 4 answers · asked by space-rocks! 1 in Science & Mathematics ➔ Astronomy & Space
This is the slow periodic change in the direction of the earth's axis of rotation as a result of external torques by the moon , sun and planets .
Once cycle of precession traces out a circle in the sky every 25,800 years. This motion results in continually changing pole stars and stellar co-ordinates
2007-03-16 16:51:14 · answer #1 · answered by spaceprt 5 · 1⤊ 0⤋
Precession refers to a change in the direction of the axis of a rotating object. In physics, there are two types of precession, torque-free and torque-induced, the latter being discussed here in more detail. In certain contexts, "precession" may refer to the precession that the Earth experiences, the effects of this type of precession on astronomical observation, or to the precession of orbital objects.
http://en.wikipedia.org/wiki/Precession
2007-03-17 00:48:42 · answer #2 · answered by neumor 2 · 0⤊ 0⤋
The resultant motion of the components causing precession of the equinoxes westward along the ecliptic at the rate of about 50.3″ per year.
2007-03-17 00:14:08 · answer #3 · answered by DeepBlue 4 · 0⤊ 0⤋
It is the slow 'wobble' of the Earth on it's axis. It's caused by every other torque in the Universe acting on the Earth. But the big ones are the moon, Sun, and other planets.
HTH âº
Doug
2007-03-17 00:00:54 · answer #4 · answered by doug_donaghue 7 · 0⤊ 0⤋