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 is in vain that we would circumscribe the power of one half of our race, and that half by far the most important and influential. If they exert it not for good, they will for evil; if they advance not knowledge, they will perpetuate ignorance. Let women stand where they may in the scale of improvement, their position decides that of the race.”
—Frances Wright (1795–1852)
“Heaven gives its glimpses only to those
Not in position to look too close.”
—Robert Frost (1874–1963)
“The teacher must derive not only the capacity, but the desire, to observe natural phenomena. In our system, she must become a passive, much more than an active, influence, and her passivity shall be composed of anxious scientific curiosity and of absolute respect for the phenomenon which she wishes to observe. The teacher must understand and feel her position of observer: the activity must lie in the phenomenon.”
—Maria Montessori (1870–1952)