[meteorite-list] Mars Express Image: Crater Dunes in Argyre Planitia

[Ron Baalke]

http://www.esa.int/export/SPECIALS/Mars_Express/SEMYRSW4QWD_0.html

Crater dunes in Argyre Planitia
European Space Agency 
Mars Express 
23 August 2004

These images, taken by the High Resolution Stereo Camera (HRSC) on board
ESA's Mars Express spacecraft, show a Martian crater with a dune field
on its floor.
 
The images were taken during orbit 427 in May 2004, and show the crater
with a dune field located in the north-western part of the Argyre
Planitia crater basin.

The images are centred at Mars longitude 303° East and latitude 43°
South. The image resolution is approximately 16.2 metres per pixel.

Crater dunes in 3D

The crater is about 45 kilometres wide and 2 kilometres deep. In the
north-eastern part of this crater, the complex dune field is 7
kilometres wide by 12 kilometres long.

In arid zones on Earth, these features are called ?barchanes?, which are
dunes having an asymmetrical profile, with a gentle slope on the
wind-facing side and a steep slope on the lee-side.

The dune field shown here suggests an easterly wind direction with its
steeper western part. The composition of the dune material is not
certain, but the dark sands could be of basaltic origin.

Crater dunes 
 
The colour image has been created from the HRSC?s nadir (vertical view)
and three colour channels. The 3D anaglyph image has been created using
the nadir and stereo channels.

The perspective views have been calculated from the digital terrain
model derived from the stereo channels.