A gully
cuts through the eastern edge of a dune field in a large, degraded crater in
the Martian southern hemisphere, as seen by the Mars Reconnaissance Orbiter HiRISE
camera.
Gullies are features found on slopes and dunes in the mid-latitudes of both
hemispheres. Scientists speculate that both slope and dune gullies may be a
result of liquid water from the surface or subsurface. Dune gullies are more
linear and have levees bordering their channels, without alcoves or debris
formations. Slope gullies often have deeply incised alcoves and channels that resemble
water-carved features such as streamlined islands.
This dune
field is unusual in that one of its gullies has features more similar to that
of a slope gully, with a deeply cut alcove and what appear to be streamlined islands
on the channel floor.
— NASA/JPL/University of Arizona and SPACE.com Staff
Credit: NASA/JPL/University of Arizona
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