Position
All planetary orbital planes wobble around the invariable plane, meaning that they rotate around its axis while their inclinations to it vary, both of which are caused by the gravitational perturbation of the other planets. That of Earth rotates with a quasi-period of 100,000 years and an inclination that varies from 0.1° to 3°. If long-term calculations are performed relative to the present ecliptic, which is inclined to the invariable plane by about 1.5°, it appears to rotate with a period of 70,000 years and an inclination that varies between 0° and 4°. Specifically, Earth's orbit (the ecliptic) is inclined to the invariable plane by 1°34'59"−18"T, where T is the number of centuries since 1900. Its J2000.0 value is 1°34'43.3". The inclination of the orbit of Jupiter to the invariable plane varies over the range of 14'–28'.
Read more about this topic: Invariable Plane
Famous quotes containing the word position:
“To be free in an age like ours, one must be in a position of authority. That in itself would be enough to make me ambitious.”
—Ernest Renan (1823–1892)
“Only the other day I was inquiring of an entire bed of old- fashioned roses, forced to listen to my ramblings on the meaning of the universe as I sat cross-legged in the lotus position in front of them.”
—Prince Charles (b. 1948)
“I think the most important education that we have is the education which now I am glad to say is being accepted as the proper one, and one which ought to be widely diffused, that industrial, vocational education which puts young men and women in a position from which they can by their own efforts work themselves to independence.”
—William Howard Taft (1857–1930)