AST352L--Spring 1998

Determining the Position of a Comet

1. Within the Orbital Plane

This assignment is DUE on Wednesday, April 8.

The elements of the orbit of Comet Encke are

a=2.2091401 AU

e=0.8502196

I=11.94524°

Longitude of Node (Big Omega)=334.75006°

Argument of Perihelion (little omega)=186.23352°

T=1990 October 28.54502, Dynamical Time

Determine the following for the position of the comet within the orbital plane, for the date 1990 October 5.0 Dynamical Time.

1. The mean motion n.
2. The mean anomaly, l.
3. The eccentric anomaly, u.
4. The true anomaly, f.
5. The radius r , using both the formula in f and the formula in u.
6. The (x,y ) position of the comet in the orbital plane, using the formulas in u.
7. The (x,y ) position of the comet in the orbital plane, using the forumlas in f (should agree with the previous result).
8. The components (xdot, ydot) of the velocity of the comet in the orbital plane, using the formulas in u.
9. The components (xdot, ydot) of the velocity of the comet in the orbital plane, using the hodograph formula (should agree with the previous result).