[meteorite-list] Mars Express Reveals Wind-blown Deposits on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 5 Feb 2012 13:42:09 -0800 (PST)
Message-ID: <201202052142.q15Lg9DT013960_at_zagami.jpl.nasa.gov>

http://www.esa.int/esaCP/SEM1NHTXXXG_index_0.html

Mars Express reveals wind-blown deposits on Mars
European Space Agency
3 February 2012

New images from ESA's Mars Express show the Syrtis Major region on Mars.
Once thought to be a sea of water, the region is now known to be a
volcanic province dating back billions of years.
 
Syrtis Major can be spotted from Earth even with relatively small
telescopes - the near-circular dark area on the planet stretches over
1300 x 1500 km.

Christiaan Huygens discovered this area in 1659 and by repeated
observations he used it to time the length of day on Mars.

Early ideas held that it was a sea with a water level that rose and
fell, causing the markings to change.

Now, however, we know that the region is volcanic in origin, devoid of
water and that the changes in its shape are due to dust and sand being
blown around in the wind.
 
[Image]
Syrtis Major in context

Newly released images of a part of Syrtis Major seen from ESA's Mars
Express orbiter show lava flows that flooded the older highland
material, leaving behind buttes - isolated hills with steep sides that
were too high to be affected.

They can be identified by their lighter colours and their eroded state,
and some even show ancient valleys on their flanks.

Individual lava flows, filled craters and partly-filled craters can be
made out in the images. The prevailing wind direction can be seen from
the dispersal of the lighter-toned dust and darker-toned sand in and
around the craters and buttes. The smaller craters illustrate this clearly.

The largest crater in the pictures has a small central peak and contains
a small dune field of darker-toned dunes to the east of its floor.

The number and size of craters can be used to date surfaces in the Solar
System because craters slowly accumulate as impacts occur over time.
This information can be used to date the volcanic province and suggests
an age of over 3 billion years.
 
[Image]
Syrtis Major features
 
[Image]
Syrtis Major elevation
 
[Image]
Syrtis Major high resolution
 
[Image]
Syrtis Major perspective

[Image]
Syrtis Major perspective
 
[Image]
Syrtis Major perspective
 
[Image]
Syrtis Major perspective
 
[Image]
Syrtis Major 3D
 
Received on Sun 05 Feb 2012 04:42:09 PM PST