Albedo objects in the outer Solar System and asteroid belt have low albedos down to about 0.05. A typical comet nucleus has an albedo of 0.04. Such a dark surface is thought to be indicative of a primitive and heavily space weathered surface containing some organic compounds. The overall albedo of the Moon is measured to be around 0.136, but it is strongly directional and non-Lambertian, displaying also a strong opposition effect. Although such reflectance properties are different from those of any terrestrial terrains, they are typical of the regolith surfaces of airless Solar System bodies. Two common albedos that are
Albedo feature Albedo feature An albedo feature is a large area on the surface of a planet (or other solar system body) which shows a contrast in brightness or darkness (albedo) with adjacent areas. Historically, albedo features were the very first (and usually only) features to be seen and named on Mars and Mercury. Early classical maps (such as those of Schiaparelli and Antoniadi) showed only albedo features, and it was not until the arrival of space probes that other surface features such as craters could be seen. On bodies other than Mars and Mercury, an albedo feature is sometimes called a