[meteorite-list] Mars Express Images: Craters Young and Old in Sirenum Fossae

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 12 Feb 2010 13:11:03 -0800 (PST)
Message-ID: <201002122111.o1CLB3p8009066_at_zagami.jpl.nasa.gov>

http://www.esa.int/SPECIALS/Mars_Express/SEMJLFSJR4G_0.html

Mars Express
Craters young and old in Sirenum Fossae
European Space Agency
3 February 2010

The Mars Express High Resolution Stereo Camera has imaged craters both
young and old in this view of the Southern Highlands of Mars.
 

[Image]
Sirenum Fossae

Part of the Sirenum Fossae region in the Southern Highlands, the area in
this image is centred at about 28??S / 185??E. The image captures an area
to the north of the Magelhaens Crater. It extends some 230 km by 127 km
and covers about 29 450 sq km, roughly the size of Belgium. The image
resolution is approximately 29 metres per pixel.
 

[Image}
Perspective view of Sirenum Fossae

Sirenum Fossae extends for more than 2500 km to the southwest of the
Tharsis volcanic region, which contains Olympus Mons, the highest
volcano in our Solar System. Sirenum Fossae is a system of grabens,
formed by stresses placed on the crust during the uprising of the
Tharsis region. A graben is visible as two sets of parallel lines
running from top to bottom to the left of centre.
 
[Image]
Sirenum Fossae's central plateau

The Southern Highlands are older than the Northern Lowlands, based on
the larger number of impact craters seen to cover the region. Craters of
50 km in diameter are common in this area and have usually suffered from
erosion, indicating they were formed during ancient times.
 
 
[Image]
Notable features in the Sirenum Fossae region of Mars.
 
There is an impact crater with a diameter of about 28 km to the left of
the image. In contrast to other craters in its vicinity, it has
experienced less erosion ??? its crater rim and central peak are still
preserved. There are three other craters nearby: to the west is a large
crater with a diameter of 56 km, to the northeast one that stretches 34
km across and a smaller crater of only 9 km diameter to the south.
 
 

[Image]
Craters in the Sirenum Fossae region of Mars

On the basis of their appearances, the craters can be placed in age
order. The largest two are the oldest because they have been partially
destroyed by the mid-sized crater. The smallest is the youngest because
it has impacted into the rim of the mid-sized crater.
 
 
[Image]
Elevation of the Sirenum Fossae region in the Southern Highlands of Mars.
 
In the central part of the image, a plateau is recognisable and shows
evidence of further erosion. In particular, there is a broad valley
system on the western slope.
 

[Image]
Part of the Sirenum Fossae region in high resolution.
 
[Image]
Part of the Sirenum Fossae region in 3D.
Received on Fri 12 Feb 2010 04:11:03 PM PST