|
|
Crater Holden and Uzboi Vallis 
These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, show the outlet channel of the Uzboi Vallis system into Crater Holden on Mars.
The valley of Uzboi Vallis begins in the region of Argyre Planitia and crosses the southern highlands in the direction of the northern lowlands. It connects several large impact craters, such as the 140 kilometre-wide Crater Holden seen in the main image.
A small, dark dune-field can be seen in the eastern half of the crater floor. It indicates the role of wind in the morphological evolution of Crater Holden.
Many smaller craters on the floor of Holden are covered with sediments, which were deposited after the formation of these craters and indicate that they are older than the unfilled small craters.
The central mount of Holden is partly hidden, because it has also been covered by sediments. The rim of the crater has been cut by gullies, which sometimes form small valley networks.
In other parts of the crater rim, the alluvial fans are less distinct and partly covered by younger ‘talus’ cones (cone-shaped piles of debris from rock falls at the base of slopes).
Later, a smaller channel was cut into the valley floor. The end of the small channel has been blocked by a landslide from the crater rim (see close-up 2).
The colour images were processed using the HRSC nadir (vertical view) and three colour channels. The perspective views were calculated from the digital terrain model derived from the stereo channels. The 3D anaglyph image was created from the nadir channel and one of the stereo channels. Stereoscopic glasses are needed to view the 3D image. Image resolution has been decreased for use on the internet.
For more information on Mars Express HRSC images, you might like to read our updated 'Frequently Asked Questions'.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
