This picture is an Extra Detail Magnification ("EDM") obtained from yesterday's interesting Contextual Image (or "CTX Frame", for short) of the Dwarf Planet 1-Ceres, taken by the NASA - Dawn Spacecraft on October, 15, 2015, that shows us a small part of its Southern Hemisphere. In this EDM view, two prominent, similarly sized and both Unnamed Impact Craters demonstrate how the so-called "Impact Features" become degraded over time (---> a LONG time, of course...). The left (Sx) Unnamed Impact Crater is younger: in fact, its Rim is still crisp and its Walls are generally smooth, peppered with only a few small Craters. On the other hand, its older twin, located to its right (Dx), has been battered by more Impacts, and the Material around its Rim has slumped and softened. In fact, the Blanket of Material ejected from the younger Impact Crater (---> such as the so-called "Ejecta Blanket"), during its formation, would have partly covered its older neighbor. Planetary Scientists like to call this slow, progressive changing of the Surface of Planetary Bodies by Cratering (such as a changing due to the occurrence of a number of impact events), as "Impact Gardening". The original photo was taken from an altitude of approx. 915 miles (such as about 1472,5461 Km) from the Surface, with a resolution of roughly 450 feet (such as about 137,16 meters) per pixel. This image (which is a crop obtained from an Original NASA - Dawn Spacecraft's b/w and NON Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 201235 - Dawn HAMO Image 72) |