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:
“Einstein is loved because he is gentle, respected because he is wise. Relativity being not for most of us, we elevate its author to a position somewhere between Edison, who gave us a tangible gleam, and God, who gave us the difficult dark and the hope of penetrating it.”
—E.B. (Elwyn Brooks)
“Unfortunately, life may sometimes seem unfair to middle children, some of whom feel like an afterthought to a brilliant older sibling and unable to captivate the family’s attention like the darling baby. Yet the middle position offers great training for the real world of lowered expectations, negotiation, and compromise. Middle children who often must break the mold set by an older sibling may thereby learn to challenge family values and seek their own identity.”
—Marianne E. Neifert (20th century)
“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)