[meteorite-list] Mars Express Images: 'Happy Face' Crater on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Apr 11 11:26:45 2006
Message-ID: <200604102312.k3ANCtm23155_at_zagami.jpl.nasa.gov>

http://www.esa.int/SPECIALS/Mars_Express/SEMMTFNFGLE_0.html

'Happy face' crater on Mars
Mars Express
European Space Agency
10 April 2006

These images, taken by the High Resolution Stereo Camera (HRSC) on board
ESA's Mars Express spacecraft, show the Galle Crater, an impact crater
located on the eastern rim of the Argyre Planitia impact basin on Mars.
 
 
[Map showing Crater Galle in context]

The HRSC obtained these images during orbits 445, 2383, 2438, 2460 and
2493 with a ground resolution ranging between 10-20 metres per pixel,
depending on location within the image strip.

The images show Crater Galle lying to the east of the Argyre Planitia
impact basin and south west of the Wirtz and Helmholtz craters, at 51?
South and 329? East.

 
 
[Perspective view of Crater Galle, looking south-east]

The images of the 230 km diameter impact crater are mosaics created from
five individual HRSC nadir and colour strips, each tens of kilometres wide.

A large stack of layered sediments forms an outcrop in the southern part
of the crater. Several parallel gullies, possible evidence for liquid
water on the Martian surface, originate at the inner crater walls of the
southern rim.

 
 
[False-colour mosaic of Crater Galle]

Crater Galle, named after the German astronomer J.G. Galle (1812-1910),
is informally known as the 'happy face' crater.

The 'face' was first pointed out in images taken during NASA's Viking
Orbiter 1 mission.

Its interior shows a surface which is shaped by 'aeolian' (wind-caused)
activity as seen in numerous dunes and dark dust devil tracks which
removed the bright dusty surface coating.

 
 
[Black and white mosaic of Crater Galle]

The colour scenes, false-colour and near true-colour, have been derived
from three HRSC colour and nadir channels gathered during five
overlapping orbits. The perspective views have been calculated from a
mosaic of digital terrain models derived from the stereo channels.

The black-and-white high-resolution image mosaic was derived from the
nadir channel which provides the highest detail of all channels. The
resolution has been decreased for use on the Internet, to around 50 m
per pixel.

 
 
[Close-up perspective view of Crater Galle, looking north]
 
[Close-up view of Crater Galle]
 
[False-colour close-up mosaic of Crater Galle]
 
 
Received on Mon 10 Apr 2006 07:12:54 PM PDT