HiRISE | Fretted Terrain Valley Traverse (PSP_009719_2230)
NASA/JPL-Caltech/UArizona
This observation shows fretted terrain in valleys located in Protonilus Mensae near the crustal dichotomy, the region that separates the Southern hemisphere highlands from the Northern hemisphere lowlands.
Fretted terrain is thought to involve movement of ice-rich material in its formation. The speckled texture of the valley fill (the fretted terrain) is probably due to sublimation, when ice goes directly from a solid to a gas, leaving behind empty space under the soil into which overlying material can collapse.
The linear striations in the valley fill mark the direction of movement. For example, in the valley near the top of the image, the material was moving across the scene (probably to the right based on images from other datasets). Also in this scene, are several small craters in various stages of degradation.
Written by: Kelly Kolb (17 December 2008)
| Acquisition date 22 August 2008 Local Mars time Latitude (centered) Longitude (East) Spacecraft altitude Original image scale range Map projected scale Map projection Emission angle
Phase angle Solar incidence angle Solar longitude For non-map projected images
| JPEG Black and white map projected non-map IRB color Merged IRB Merged RGB RGB color JP2 IRB color JP2 EXTRAS IRB color Merged IRB Merged RGB RGB color |
ADDITIONAL INFORMATION B&W label Color label Merged IRB label Merged RGB label EDR products HiView NB Black & white is 5 km across; enhanced color about 1 km USAGE POLICY POSTSCRIPT |
