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
Albedo (alchemy) Albedo (alchemy) In alchemy, albedo is one of the four major stages of the magnum opus; along with nigredo, citrinitas and rubedo. It is a Latinicized term meaning "whiteness". Following the chaos or "massa confusa" of the nigredo stage, the alchemist undertakes a purification in albedo, which is literally referred to as "ablutio" – the washing away of impurities. In this process, the subject is divided into two opposing principles to be later coagulated to form a unity of opposites or "coincidentia oppositorum" during rubedo. Titus Burckhardt interprets the albedo as the end of the lesser work, corresponding to a