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This Absolute Natural Color image-mosaic of the huge Rachmaninoff Crater (whose diameter is approx. 306 Km - such as about 190 miles) highlights, just like in yesterday's APOD, the so very many unique Features that characterize this fascinating Mercurian Impact Basin. Here, the Inner Ring of Rachmaninoff's Double Ring Structure appears of a dark gray color, which, as we already underlined yesterday, is a clear proof that the Mountains forming the Inner Ring are made of (or covered by) Low Reflectance Material (or LRM for short - such as some kind of Material which possesses a very low Albedo). This dark gray color of the Inner Ring of Rachmaninoff makes a quite sharp contrast with the lighter (i.e.: orange/brown) color of the Outer Ring (i.e.: brown) as well as with the Inner Ring Floor, in which many Concentric Troughs (---> Cracks of the Surface) are also well visible. Scattered Hollows located all across the Tops of the Peak Rings also add to the range of interesting Surface Features that can be found in this simply magnificent Impact Crater. Date acquired: January, 13th, 2012 This picture (which is an Original NASA - MESSENGER Spacecraft color frame published on the NASA - Planetary Photojournal with the ID n. PIA 15861) has been additionally processed and then re-colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - MESSENGER Spacecraft and then looked down, towards the Surface of Mercury), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Mercury, each having a different Albedo (---> Reflectivity) and Chemical Composition. |