PIA04116: Martian Gullies


Martian Gullies

Caption:

25 July 2005
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a gullied crater wall in the Terra Sirenum region of Mars. The fluids that formed the gully channels and deposited debris in aprons at the base of the crater wall may have percolated through layers in the layered bedrock exposed in the crater wall. As fluid seeped out of the ground, it undermined overlying layers of rock, and caused the formation of several compex alcoves, higher in the crater wall. The formation of alcoves requires the undermining and collapse of layered material at a point where the channel begins; this is a key observation supporting the hypothesis that martian gullies require groundwater, not snowmelt or other exotic processes or fluids, to form.

Location near : 37.3°S, 153.2°W
Image width : width: ~3 km (~1.9 mi)
Illumination from : upper left
Season : Southern Spring

Cataloging Keywords:

Name Value Additional Values
Target Mars
System
Target Type Planet
Mission Mars Global Surveyor (MGS)
Instrument Host Mars Global Surveyor
Host Type Orbiter
Instrument Mars Orbiter Camera (MOC)
Detector
Extra Keywords Crater, Grayscale, Water
Acquisition Date
Release Date 2005-07-25
Date in Caption 2005-07-25
Image Credit NASA/JPL/Malin Space Science Systems
Source photojournal.jpl.nasa.gov/catalog/PIA04116
Identifier PIA04116