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:
“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)
“Feminism, like Boston, is a state of mind. It is the state of mind of women who realize that their whole position in the social order is antiquated, as a woman cooking over an open fire with heavy iron pots would know that her entire housekeeping was out of date.”
—Rheta Childe Dorr (1866–1948)
“You will belong to that minority which, according to current Washington doctrine, must be protected in its affluence lest its energy and initiative be impaired. Your position will be in contrast to that of the poor, to whom money, especially if it is from public sources, is held to be deeply damaging.”
—John Kenneth Galbraith (b. 1908)