Posted by Bobby on .
If you know the mass of a star and a planet’s radius and speed at perihelion (closest approach to the star), then using conservation of energy and angular momentum you can solve for the radius and speed of that planet at aphelion (farthest point from the star).
Encke’s comet has speed 7.0x104
m/s at its closest distance to the Sun (5.1x1010 m, about a third of the distance from the Earth to the Sun). What is its speed and distance from the
Sun at aphelion?