[meteorite-list] Mars Global Surveyor Impact Crater Photos

[Ron Baalke]

MGS Impact Crater Photos

Here are new Mars Global Surveyor impact crater photos released
today. The MGS photos revealed that 20 new craters between 2 
and 150 metres across have appeared on Mars since 1999.

Ron Baalke

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http://www.jpl.nasa.gov/multimedia/slideshows/mgs-20061206/slide6.cfm

Groundwater May Be Responsible     

Gullies beneath a small crater on the rim of a larger 
crater. This image supports the hypothesis that the 
fluid responsible for the gullies came from beneath 
the ground, either as groundwater or melting of 
subsurface ice. The impact that created the larger 
crater caused an initial set of subsurface fractures. 
Then, fractures from the second, smaller impact provided 
pathways for groundwater to reach the surface on the wall 
of the larger crater and spill down the slope. 

Full image and caption:

http://www.nasa.gov/mission_pages/mars/images/pia09031.html

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http://www.jpl.nasa.gov/multimedia/slideshows/mgs-20061206/slide7.cfm

Impact Craters

Before-and-after views of an impact site. The top image 
was acquired in 2002, the lower one in 2006. Details 
evident at the impact site show how the blast moved dust 
around and interacted with craters and other small 
obstacles on the ground

Full image and caption:

http://www.nasa.gov/mission_pages/mars/images/pia09023.htm

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http://www.jpl.nasa.gov/multimedia/slideshows/mgs-20061206/slide8.cfm

Fresh Crater with Light-Toned Ejecta

While most of the new impact craters found on Mars by 
Mars Global Surveyor have dark ejecta patterns, a few 
of them also have light-toned ejecta, indicating that 
the impacting meteorite excavated to a depth where a 
light-toned material was present. This crater is in 
Arabia Terra.

Full image and caption:

http://www.nasa.gov/mission_pages/mars/images/pia09025.html

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http://www.jpl.nasa.gov/multimedia/slideshows/mgs-20061206/slide10.cfm

New Craters

The left image was taken in 2001. At right is the 
"discovery" image, acquired in 2006. In each case, a 
white box indicates the location of the Mars Orbiter 
Camera narrow-angle image for which the context image 
was obtained. For scale, the white boxes are 3 
kilometers (1.9 miles) wide. 

Full image and caption:

http://www.nasa.gov/mission_pages/mars/images/pia09020.html

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