Definition: The ratio of the light reflected by a body to the light received by it. Albedo values range from
0 (pitch black) to 1 (perfect reflector).
Technical Definition: Geometric albedo is the ratio of a body's brightness at zero phase angle
to the brightness of a perfectly diffusing disk with the same position and apparent size as the body.
Our Moon has a very low albedo (0.07), while Venus has a high albedo (0.60). The albedo combined with the
absolute magnitude can help determine the size of an asteroid.