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:
“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)
“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)
“I repeat, sir, that in whatever position you place a woman she is an ornament to society and a treasure to the world. As a sweetheart, she has few equals and no superiors; as a cousin, she is convenient; as a wealthy grandmother with an incurable distemper, she is precious; as a wet-nurse, she has no equal among men. What, sir, would the people of the earth be without woman? They would be scarce, sir, almighty scarce.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)