Astronomy Picture of the Day - powered by LUNEXIT.IT

These beautiful brown/orange Dunes, located in the Aonia Terra Region of Mars (Aonia Terra lies in the Southern Hemisphere of the Red Planet, with Center Latitude at 62,0° and Center Longitude at 100,0° West) are being periodically monitored by the NASA - Mars Reconnaissance Orbiter, in order to register any change - if it actually occurs - in their external physical characteristics and features (for instance, one reason of the visual monitoring of the Aonian Dunes is to verify and then to analize the creation and/or the modification of those Gullies which, sometime, form on them during the Winter, as a consequence of the action of Carbon Dioxide (CO2) Frost on the Sand forming the Dunes themselves).

The season in which this image has been acquired was the late Fall of the Southern Hemisphere, when Frost had just started accumulating (a whitish patch of CO2 Frost can be seen on the right lower side of the frame, all over the illuminated portion of a series of almost parallel and very thin Ripples), with an higher concentration of it (such as the Frost) that is located on the South Pole-facing Slopes of the Dunes and in the Troughs existing between the Ripples.

Mars Local Time: 15:10 (Early Afternoon)
Coord. (centered): 49,8° South Lat. and 293,1° East Long.
Spacecraft altitude: 250,1 Km (such as about 156,3 miles)
Original image scale range: 50,0 cm/pixel (with 2 x 2 binning) so objects ~ 1 mt and 50 cm across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR

Emission Angle: 0,3°
Phase Angle: 82,9°
Solar Incidence Angle: 83° (meaning that the Sun is about 7° above the Local Horizon)
Solar Longitude: 58,6° (Northern Spring)
Credits: NASA/JPL/University of Arizona

This frame has been colorized in Absolute Natural Colors by (such as the colors that a human eye would actually perceive if someone were onboard the 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.