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 place oneself in the position of God is painful: being God is equivalent to being tortured. For being God means that one is in harmony with all that is, including the worst. The existence of the worst evils is unimaginable unless God willed them.”
—Georges Bataille (1897–1962)
“It’s a fact that it is much more comfortable to be in the position of the person who has been offended than to be the unfortunate cause of it.”
—Barbara Walters (b. 1931)
“Beauty ought to look a little surprised: it is the emotion that best suits her face.... The beauty who does not look surprised, who accepts her position as her due—she reminds us too much of a prima donna.”
—E.M. (Edward Morgan)