These images and the stereo anaglyph show an interesting region of Mars on the giant Tharsis rise, East of Olympus Mons.
There are well-preserved channels and lava flows. HiRISE has acquired 6 stereo pairs as a mosaic over this area. The science goal is to understand the relationships between channels and lava, which are often closely associated on Mars.
The simplest hypothesis is that the lava carved the channels, but we don’t understand how lava can deeply erode into bedrock. The generally favored hypothesis is that water carved the channels, and later eruptions of lava followed the already-carved channels, or maybe lava and water flows were interleaved in time.
Floodwaters on Mars may originate from the subsurface, and require fractures to reach the surface. Lava may exploit these same fractures, and the magma at depth may have melted ice to contribute to the water. On the other hand, the water flood may have been much older than the lava eruptions. The channels appear relatively young, but have been coated by younger lava. Many questions remain about these relationships, and high-resolution topographic data is needed to model the processes and deduce the geologic history.
Written by: Alfred McEwen (9 February 2011)
This is a stereo pair with ESP_020261_2010 .
More info and image formats at http://hirise.lpl.arizona.edu/ESP_020683_2010
Image: NASA/JPL/University of Arizona