Sample Problem
Comet Halley orbits about the Sun with a period of 76 years and. in 1986. had a distance of closest approach to the Sun. its perihelion distance . shows that this is between the orbits of Mercury and Venus.
(a) What is the comet’s farthest distance from the Sun. its aphelion distance Ru?
SOLUTION:The Key idea comes from F. in which we see that RQ + R,. = la. where a is the semi major axis of the orbit of comet.
(b) What is the eccentricity e of the .orbit of comet Halley?
SOLUTION: The Key Idea here is that we can relate e, a, and Rp via Fig. 14-13. We see there that ea = a – Rp.
This cometary orbit, with an eccentricity approaching unity, is a long thin ellipse.
