Photo Agency - Astronomy - Space - Nature

> Mars: gullies on impact crater wall

Mars: gullies on impact crater wall

author: Nasa/JPL/University of Arizona/Novapix

reference: a-mar11-00086

Image Size 300 DPI: 21 * 16 cm

Gullies, on Earth, are usually formed through the action of liquid water. Whether gullies form under today's cold dry conditions on Mars is a major question that planetary scientists are trying to answer. The gullies pictured here in Hale crater are great examples of what a typical Martian gully looks like. Wide V-shaped channels running downhill (from top to bottom) where the material that carved the gully flowed. At the bottom of the channel this material empties out onto a fan-shaped mound. Several gullies are visible here and the fans from each gully overlap one other in complicated ways. Image taken on august 3, 2009 by the HIRISE camera on NASA's Mars Reconnaissance Orbiter.

Keywords for this photo:

2009 - ASTRONOMY - GULLY - HALE - HIRISE - IMPACT CRATER - MARS - MARS RECONNAISSANCE ORBITER - MRO - PLANET - WATER -