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:
“He who is usually self-sufficient becomes exceptionally vain and keenly alive to fame and praise when he is physically ill. The more he loses himself the more he has to endeavor to regain his position by means of the opinion of others.”
—Friedrich Nietzsche (1844–1900)
“When asked whether or not we are Marxists, our position is the same as that of a physicist or a biologist who is asked if he is a “Newtonian” or if he is a “Pasteurian.””
—Ernesto “Che” Guevara (1928–67)
“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)