Western Arabia Terra - Mars Express
Western Arabia Terra imaged by the Mars Express HRSC instrument. This image captures the transition from the rugged equatorial highland terrain of Arabia Terra as it transitions into the relatively featureless northern lowland region of Acidalia Planitia. Although this region is among the oldest locations on the Martian surface, the geology is unspectacular, consisting of generally unmodified craters, few tectonic features, and relatively few channels carved by water. In the absence of attention from geologists, very few of the craters in this region have been named.
This image was captured in the middle of Martian summer, when Mars is near its furthest from the Sun. During this period, the Martian atmosphere cools substantially, allowing daytime water ice clouds to form at equatorial latitudes across the entire planet for a few months. This phenomenon, called the Aphelion Cloud Belt, was active in this photo, although the clouds associated with it were beginning to thin for the season when this image was taken.
This image was created using two limb-scan images taken through Mars Express' blue and green filters. These sequences are designed to study Martian atmospheric layers. These sequences require a complex geometric correction to resemble what a human eye might see. In addition, a red channel has been synthesized by subtracting blue channel data from the green channel data.
This image was taken during Mars Express' 15481st orbit of the red planet, March 19, 2016.
Image Credit: ESA/DLR/FU Berlin/J. Cowart, CC BY-SA 3.0 IGO