THEMIS Image of the Day, April 15, 2019. Today’s VIS image is located in an unnamed crater in Arabia Terra. Dark blue in this combination is typically basaltic sands. The presence of sand dunes with this tone indicated that these dunes are of basaltic composition.
The THEMIS VIS camera contains 5 filters. The data from different filters can be combined in multiple ways to create a false color image. These false color images may reveal subtle variations of the surface not easily identified in a single band image.