Figure 11-40: R I V U X G
Martian Gullies (a) When the Mars Global Surveyor spacecraft looked straight down into this crater in the Martian southern hemisphere, it saw a series of gullies along the crater wall. These gullies may have formed by subsurface water seeping out to the surface, or by the melting of snow that fell on crater walls. (b) These two images of a southern hemisphere crater were taken six years apart. The new deposit seen in 2005 may have been caused by a subsurface melt, or might be a landslide unassociated with liquid water.
Martian Gullies (a) When the Mars Global Surveyor spacecraft looked straight down into this crater in the Martian southern hemisphere, it saw a series of gullies along the crater wall. These gullies may have formed by subsurface water seeping out to the surface, or by the melting of snow that fell on crater walls. (b) These two images of a southern hemisphere crater were taken six years apart. The new deposit seen in 2005 may have been caused by a subsurface melt, or might be a landslide unassociated with liquid water.
(a and b: NASA/JPL/Malin Space Science Systems)