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:
“People who are in a fortunate position always attribute virtue to what makes them so happy.”
—John Kenneth Galbraith (b. 1908)
“Being in a family is like being in a play. Each birth order position is like a different part in a play, with distinct and separate characteristics for each part. Therefore, if one sibling has already filled a part, such as the good child, other siblings may feel they have to find other parts to play, such as rebellious child, academic child, athletic child, social child, and so on.”
—Jane Nelson (20th century)
“Heaven gives its glimpses only to those
Not in position to look too close.”
—Robert Frost (1874–1963)