(a) at what point in its orbit is the planet moving the fastest . (b) at what point is it moving the slowest .
For a satellite of the Earth, the Apogee is the point of its orbit when it is farthest from the Earth, and the Perigee is the point of its orbit when it is closest to the Earth.
For a satellite of a body that is not the Earth, the general terms are Apoapsis and Periapsis.
For a satellite of the Sun, the terms are Aphelion and Perihelion.
For a satellite of a body that is not the Earth, the general terms are Apoapsis and Periapsis.
For a satellite of the Sun, the terms are Aphelion and Perihelion.
Kepler's 2^{nd} Law of Planetary Motion dictates that a planet's fastest speed is at Perihelion and its slowest at Aphelion.
[Kepler's 2^{nd} Law of Planetary Motion: A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.]