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Posted on Wednesday, June 09, 2004 @ 8:38 AM PDT by bjs |
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The High Resolution Stereo Camera on board the European Space Agency's Mars
Express spacecraft has spotted evidence of flooding in a region on the
south-western portion of Mars' Tharsis bulge. The small-scale chaotic
terrain is characterized by isolated blocks of surface material which,
according to theory, were randomly arranged during the release of subsurface
water and subsequent collapse of the surface.
From
European Space Agency:
Evidence of flooding at Mangala Valles
These images of fluvial surface (see at bottom page) features at
Mangala Valles on Mars were
obtained by the High Resolution Stereo Camera (HRSC) on board the
ESA Mars
Express spacecraft.
The HRSC has imaged structures several times which are related to fluvial
events in the past on Mars.
The region seen here is situated on the south-western Tharsis bulge and
shows the mouth of the Mangala Valles and Minio Vallis outflow channels.
The source of the outflow channel is related to the Mangala Fossa, a fissure
running east-west for several hundred kilometers.
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One theory about its formation is related to a process known on Earth as
'dyke emplacement'.
This is when hot molten rock finds its way to the surface through a fissure,
releasing large amounts of water by the melting of subsurface ice.
It is still unclear for how long and to what extent water, mud or even ice
masses and wind have carved the channel here.
This theory on its formation has several analogues on Earth. Events like the
one proposed for Mangala Valles occur on Earth, for example in Iceland,
where volcanic activity causes episodic releases of water from subsurface
reservoirs, causing catastrophic floods.
Along the channel troughs, areas with so-called 'chaotic terrain' features
favor the idea of the existence of subsurface ice.
The small-scale chaotic terrain is characterized by isolated blocks of
surface material which have been randomly arranged during the release of
subsurface water and subsequent collapse of the surface. |
Location of Mangala
Valles
"click" to enlarge |
Huge areas of chaotic terrain can be found near the source areas of the
outflow channels around
Chryse Planitia, such as Kasei,
Maja and Ares Valles.
Beside the large outflow channels, a variety of smaller 'dendritic' valley
networks with a number of tributary valleys can be seen near the main
channels. This indicates possible precipitation.
The below images were taken during orbit 299 with a resolution of 28 meters per
pixel. The image centre is located at 209° E longitude and 5° S latitude.
For practical use on the internet, the images have been reduced in
resolution.
The red/cyan 3D anaglyph image was created using the stereo- and nadir
channels of the HRSC. The perspective view was calculated from the digital
terrain model derived from the stereo and color information of the image
data. The 3D images require stereoscopic glasses to view.
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"click" to
enlarge images
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Color image of
Mangala Valles |
Perspective view of
Mangala Valles |
3D image of Mangala
Valles |
Water in Mars?
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