satellite - any object which travels around another object because
of their mutual gravitational attraction. The satellite constantly
falls toward the heavier object, but forever misses it because of
its momentum perpendicular to the line between them. The path
of the satellite around the heavier object is called its orbit,
and its state of motion is called orbiting. In most cases
the satellite repeats the same orbit over and over, but when very
close to highly non-spherical objects the satellite's orbit can
change rapidly.