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:
“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)
“You do not become a “dissident” just because you decide one day to take up this most unusual career. You are thrown into it by your personal sense of responsibility, combined with a complex set of external circumstances. You are cast out of the existing structures and placed in a position of conflict with them. It begins as an attempt to do your work well, and ends with being branded an enemy of society.”
—Václav Havel (b. 1936)
“Because it is not always easy for an adult to predict what inaccurate ideas a child may have, it can help to answer questions first with one of your own: “What do you think?” Once you find out what a child is really asking, you’ll be in a better position to give a helpful answer based on the facts.”
—Joanna Cole (20th century)