Huo Hsing Vallis

Scaled Image

Image Credit: NASA/JPL/ASU

About this image

A portion of an ancient channel called the Huo Hsing Vallis is seen in the center of this image. As with all channel forms on Mars, it was carved by some moving fluid but that fluid can not automatically be assumed to be water. Lava and even wind can sculpt channel forms that mimic those of flowing water. In this case, the presence of pronounced xbow bends in the channel favors the conclusion that water was the fluid. It is interesting that the ripple-like sand ridges on the channel floor mimic current ripples found in many streams on Earth. But the fluid responsible for their formation likely is the wind. Similar ripples occur in many places on Mars that have no relationship to channels. Surrounding the channel is an intensely eroded landscape known as etched terrain. The many layers that were deposited in the past are now being eroded away by the wind. In the process, unusual polygonal ridges are being exposed, the most prominent of which appear just north of the oxbow bends. The mechanism by with they form is poorly understood. It is possible that they began as polygonal troughs similar in form and origin as those that form in permafrost regions on Earth like the Canadian Arctic. If the troughs were subsequently filled in by sediment that solidified into a more resistant deposit than the surrounding material, later erosion would leave behind ridges in place of the former troughs. Known as inverted topography, there are examples of this type of landform in other etched terrains on Mars.

Please see the THEMIS Data Citation Note for details on crediting THEMIS images. 


Image ID: 
V01608003 (View data in Mars Image Explorer)
2002-04-25 16:47
Wed, 2002-06-05
1024 pixels (19 km)
3648 pixels (67 km)
0.018545 km/pixel
0.018679 km/pixel


PNG | JPEG (high res) | JPEG (reduced res) | PDF | TIFF