Proctor Crater Dunes (Natural Colors; credits: Lunar Explorer Italia)

In the winter the dunes in Proctor Crater are covered with seasonal carbon dioxide frost (dry ice). In the spring, the frost gradually evaporates but lingers in protected regions. In this color image bright ice deposits in sheltered areas highlight the ripples on the dunes.

These dunes were imaged during the first year of MRO’s mission. Images taken now in the second Martian spring can be compared to the previous year to study interannual variability.

Mars Local Time: 15:59 (middle afternoon)
Coord. (centered): 47,2° South Lat. and 34,0° East Long.
Spacecraft altitude: 254,5 Km (such as about 159,1 miles)
Original image scale range: 50,9 cm/pixel (with 1 x 1 binning) so objects ~1,53 mt across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 8,2°
Phase Angle: 70,3°
Solar Incidence Angle: 77° (meaning that the Sun is about 13° above the Local Horizon)
Solar Longitude: 160,1° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer Italia