Albedo refers to the amount of solar radiation reflected by an object. Specifically, it is the ratio of reflected to incident solar radiation. Albedo is derived from the Latin albus, which means “to be white.” Albedo is a unitless measure of reflectivity that varies from 0 (no reflectance) to 1 (complete reflectance), although it is also commonly shown as a percentage (0% to 100%). The albedo of an object is a function of the surface properties of the object (i.e., color, roughness, transparency), the zenith angle of the sun, and the wavelength of the incident radiation. Albedo is usually determined based on the visible portion of the spectrum (0.4–0.7 µm [micrometer]).

Planetary albedo is the fractional amount of solar radiation reflected by Earth (both the atmosphere ...