This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: SemiMajor Axis (a) = Distance from the planet to the sun (in AU) The Astronomical Unit (AU) is a unit of distance It is used to measure distances to planets. 1 AU = Earths distance from the sun =93,000,000 miles P = orbital period in years A = semi major axis in AU An example: the planet Uranus orbits the sun at a distance of 19 AU So its semi major axis is a = 19 AU Question: how long does it take Uranus to orbit the sun? P2=a3 A3 = a x a x a = 19 x 19 x 19 = 6859 P2 = a3 = 6859, so p= the square root of 6859 = 83 yearsKeplers third law also applies to satellites orbiting earth. The faster the orbital period (p), the smaller the orbit (a)A close satellite orbits in just 90 minutesA satellite at about 6R earth orbits in 24 hours...
View
Full Document
 Spring '11
 McCarthy
 Planet, Astronomical unit, Kepler's laws of planetary motion, Celestial mechanics, Semimajor axis

Click to edit the document details