Geometric albedo node of their orbit, and hence lie on the ecliptic. In practice, measurements at small nonzero phase angles are used to derive the parameters which characterize the directional reflectance properties for the body (Hapke parameters). The reflectance function described by these can then be extrapolated to zero phase angle to obtain an estimate of the geometric albedo. For very bright, solid, airless objects such as Saturn's moons Enceladus and Tethys, whose total reflectance (Bond albedo) is close to one, a strong opposition effect combines with the high Bond albedo to give them a geometric albedo above unity (1.4 in the
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