Albedo formula_5 (also called blue-sky albedo) can then be given as: Directional-hemispherical reflectance is sometimes referred to as black-sky albedo and bi-hemispherical reflectance as white-sky albedo. These terms are important because they allow the albedo to be calculated for any given illumination conditions from a knowledge of the intrinsic properties of the surface. The albedos of planets, satellites and minor planets such as asteroids can be used to infer much about their properties. The study of albedos, their dependence on wavelength, lighting angle ("phase angle"), and variation in time comprises a major part of the astronomical field of photometry. For small
Dynamic Albedo of Neutrons Yellowknife Bay area in the Glenelg terrain. On August 19, 2015, NASA scientists reported that the DAN instrument on "Curiosity" detected an unusual hydrogen-rich area, at "Marias Pass," on Mars. The hydrogen found seemed related to water or hydroxyl ions in rocks within three feet beneath the rover, according to the scientists. Dynamic Albedo of Neutrons The Dynamic Albedo of Neutrons (DAN) instrument is an experiment mounted on the Mars Science Laboratory "Curiosity" rover. It is a pulsed sealed-tube neutron source and detector used to measure hydrogen or ice and water at or near the Martian surface. DAN was provided