Ius Chasma In False Color

THEMIS has taken some great pictures of Valles Marineris, the largest canyon in the solar system. If this canyon were on Earth, it would stretch from New York to Los Angeles. Image of the Day toured some of the canyons that make up this vast system.
This daytime false-color image was collected during the southern spring season.
The THEMIS VIS camera is capable of capturing color images of the Martian surface using its 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 the use of 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 single full-color 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.