Image Title: Gangis Chasma
Source: Viking Orbiter
This image is a straight-forward representation of a small corner of Valles Marineris. The only artistic license taken with this image was to airbrush in some terrain to fill in a missing section in the image and to colorize the image. The area shown in the Gangis Chasma image is of the region of the junction of Gangis Chasma and Capri Chasma, both part of the much larger Valles Marineris system.
Source Image Background
This picture is a mosaic of images taken by the Viking Orbiter 1. The orbiter view is towards the south. Gangis Chasma continues off to the east (towards the right) in the image and Capri Chasma is at the extreme left of the image. Note that the actual junction has been cropped out of the version shown above but can be seen in the raw composite shown in Figure 1 below. The approximate location of this image on Mars is 9ºS, 42ºW. For scale, the crater that sits atop the south wall of the chasma is approximately 15 kilometers wide from left to right.
For detailed information about the geology seen in this image, see "Geology of the Valles Marineris: First Analysis of Imaging From the Viking 1 Orbiter Primary Mission" by Karl R. Blasius, James Cutts, John E. Guest, Harold Masursky, published in the Journal of Geophysical Research, Vol. 82, No. 28, September 30, 1977.
Figure 1. The raw Viking images used to construct Gangis Chasma.
All processing of this image was done using Adobe Photoshop. Substantial cleaning, contrast/brightness adjustment, and digital airbrushing was required to create a seamless composite of the seven individual Viking Orbiter frames which comprise this final composite. Color was synthesized by creating three separate images and recombining them so that each image represented one of the three color channels (RGB). The final printed image is 13.5 by 10.5 inches at 300dpi. You may also note that the image of Gangis Chasma shown here is actually a subsection of the original full image. Cropping was necessary in order to produce an acceptable rectangular shape.
I have created a low resolution, cropped version of Gangis Chasma for use as a desktop wallpaper. This wallpaper version of Gangis Chasma is made available for your personal use only. It is not to be modified or redistributed in any form by any means. All rights are retained by the artist.
Gangis Chasma, 1024 x 768 Wallpaper Image by Jim Plaxco