Astronomy Picture of the Day - powered by LUNEXIT.IT

This is an image of an ancient Unnamed Impact Crater that is located in the Southern Martian Region known as Terra Cimmeria. The frame was acquired when the Sun was just 11° above the Local Horizon, so that a long and dark shadow had already extended over most of the Crater Interior. However, since there still was a diffuse illumination coming from the Martian Sky (which, according to NASA, remains relatively bright for some time even after Sunset - as well as it is appears of a bright pinkish color even quite some time before Dawn), the HiRISE Camera that is onboard the NASA - Mars Reconnaissance Orbiter had the chance and the ability to acquire sufficient signal even over faint targets (like this one), so to make useful images. The Crater Interior, once you look at it carefully (and, in spite of the poor illumination, a lot of details can be easily seen), shows a distinct pattern of Ridges and Mounds which are suggestive of the occurrence of an Icy Flow (a phenomenon that is relatively common at this Latitude).

Mars Local Time: 15:08 (Early Afternoon)
Coord. (centered): 44,814° South Lat. and 264,976° East Long.
Spacecraft altitude: 247,7 Km (such as about 154,8 miles)
Original image scale range: 49,6 cm/pixel (with 2 x 2 binning) so objects ~ 1 mt and 49 cm across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 0,3°
Sun - Mars - MRO (or Phase) Angle: 79,1°
Solar Incidence Angle: 79° (meaning that the Sun was about 11° above the Local Horizon at the time that the picture was taken)
Solar Longitude: 58,6° (Northern Spring - Southern Autumn)
Credits: NASA/JPL/University of Arizona

This frame has been 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.