Today's APOD is just an Extra Detail Magnification (or "EDM", for short) of an HiRISE image taken by the NASA - Mars Reconnaissance Orbiter on June, 4, 2014, that shows us the Southern portion of what is commonly known as a "Impact Crater with Pedestal" (in this case, it is an "Unnamed" one), and this defnition comes from the fact that the Level of the Surface adjacent to the Impact Crater itself is elevated (---> raised) in relation (---> as) to the Surface of Surrounding Terrain. The Raised Surface shows patterns and a general outline resembling what Ejecta would look like after being thrown out from the Crater during (and by) the Impact Event. In fact, this specific Impact probably occurred at a time when the Surface of the whole scene was at the Level of the (now) Raised Surface. The Ejecta landed on the part of this Surface which is close to the Crater, then the occurrence of several Erosional Phoenomena removed more Material from the rest of the scene while the Impact Ejecta - somehow - "shielded" the area around the Impact Crater, protecting the Ground under it from further erosion and kept it at an higher Level. The Eroded - or "missing", if you want - Terrain in the rest of the area (not visible here: if you want to take a look, please refer to yesterday's APOD. You can find it in the Archives - click on Archives; you will find it to the lower right - Dx - of the APOD Page), NASA's Planetary Scientists said, might have also contained (Water) Ice. The presence of Lobe shapes at the base of the Raised Ejecta and Polygons (only visible when zoomed in) on the Surface, in fact, both suggest that the Material forming the Pedestal may have contained (or may still contain) Water Ice (but we, as IPF, seriously doubt this - truly unsupported, in our humble opinion - assumption). If you look at this picture really carefully, you may be able to notice that most of the Pedestal shows the presence of a complex network of Cracks (with some of them which appear, by the way, relatively recent) and, in addition to those, also the typical markings left by the passage of Dust Devils can be seen on the lower, central portion of the Pedestal itself (as well as all the way around the Impact Crater, if you go take a look at yesterday's Contextual Frame (or "CTX Frame" for short). Last, but not least, the Pattern of the Ejecta is asymmetric around the Impact Crater, thus suggesting that the Impactor could and should have hit the Ground traveling from the North/East and following a - remarkably - Oblique Angle as to the hit Surface. Mars Local Time: 15:19 (Early Afternoon) This picture (which is a NASA - Original Mars Reconnaissance Orbiter b/w and Map-Projected frame identified by the serial n. ESP_036815_2330) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced, Gamma corrected, and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Reconnaissance Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. |