Does Earth's tilt change as it rotates around the sun?
2 Answers
No as it would violate the conservation of angular momentum.
Explanation:
The Earth's axial tilt points in the same direction with respect to the fixed stars as the Earth orbits the Sun.
The law of conservation of angular momentum does not allow it to change unless an external force is applied. It would require a very significant force to do this.
The fact that the axial tilt points in the same direction explains the seasons.
The axial tilt does precess slowly with a period of about 26,000 years do to the gravity of the Sun and other planets.
Yes
Explanation:
There is a wobble to the Earth's axis, on a 41,000 year cycle. This is cause by something called planetary perturbation. If I understand it correctly it is when there are more than one source of gravity working on an object. So the effect of gravity from the Moon and each of the planets in the solar system work together to put the Earth on this 41,000 year cycle.
http://earthobservatory.nasa.gov/Features/Milankovitch/milankovitch_2.php
The current angle of the Earth's tilt is 23.5 degrees but it is decreasing. The range of the 41,000 years cycle is roughly from 22.5-24.5 degrees.
