Arabia Terra Crater - False Color

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. Today's false color image shows an unnamed crater in Arabia Terra. Arabia Terra is one of the oldest surface regions on Mars and contains a large variety of surface features. The region is dissected with numerous unnamed channels of all sizes and complexities, as well as numerous pits of unknown origin. The blue features on the crater floor are sand dunes, in this false color combination blue indicates basaltic sands. The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation. Orbit Number: 88036 Latitude: -7.46789 Longitude: 356.08 Instrument: VIS Captured: 2021-10-19 04:28 https://photojournal.jpl.nasa.gov/catalog/PIA25385