Andrew Yee[_1_]
February 7th 08, 05:20 AM
ESA News
http://www.esa.int
25 January 2008
Traces of the martian past in the Terby crater
The High Resolution Stereo Camera (HRSC) on board ESA's Mars Express has
returned striking scenes of the Terby crater on Mars. The region is of great
scientific interest as it holds information on the role of water in the
history of the planet.
The image data was obtained on 13 April 2007 during orbit 4199, with a
ground resolution of approximately 13 m/pixel. The Sun illuminates the scene
from the west (from above in the image).
Terby crater lies at approximately 27 deg south and 74 deg east, at the
northern edge of the Hellas Planitia impact basin in the southern hemisphere
of Mars.
The crater, named after the Belgian astronomer Francois J. Terby (1846
1911), has a diameter of approximately 170 km. The scene shows a section of
a second impact crater in the north.
Eye-catching finger-shaped plateaux extend in the north-south direction.
They rise up to 2000 m above the surrounding terrain. The relatively old
crater was filled with sediments in the past, which formed plateaux on
erosion.
The flanks of the plateaux clearly exhibit layering of different-coloured
material. Differences in colour usually indicate changes in the composition
of the material and such layering is called 'bedding'. Bedding structures
are typical of sedimentary rock, which has been deposited either by wind or
water. Different rock layers erode differently, forming terraces.
The valleys exhibit gullies, or channels cut in the ground by running
liquid, mainly in the northern part of the image. These gullies and the
rock-bedding structure indicate that the region has been affected by water.
The sediments in this region are interesting to study because they contain
information on the role of water in the history of the planet. This is one
of the reasons why Terby crater was originally short listed as one of 33
possible landing sites for NASA's Mars Science Laboratory mission, planned
for launch in 2009.
The colour scenes have been derived from the three HRSC colour channels and
the nadir channel. The perspective views have been calculated from the
digital terrain model derived from the HRSC stereo channels. The 3D anaglyph
image was calculated from the nadir channel and one stereo channel,
stereoscopic glasses are required for viewing.
[NOTE: Images supporting this release are available at
http://www.esa.int/esaSC/SEMSEWEMKBF_index_1.html ]
http://www.esa.int
25 January 2008
Traces of the martian past in the Terby crater
The High Resolution Stereo Camera (HRSC) on board ESA's Mars Express has
returned striking scenes of the Terby crater on Mars. The region is of great
scientific interest as it holds information on the role of water in the
history of the planet.
The image data was obtained on 13 April 2007 during orbit 4199, with a
ground resolution of approximately 13 m/pixel. The Sun illuminates the scene
from the west (from above in the image).
Terby crater lies at approximately 27 deg south and 74 deg east, at the
northern edge of the Hellas Planitia impact basin in the southern hemisphere
of Mars.
The crater, named after the Belgian astronomer Francois J. Terby (1846
1911), has a diameter of approximately 170 km. The scene shows a section of
a second impact crater in the north.
Eye-catching finger-shaped plateaux extend in the north-south direction.
They rise up to 2000 m above the surrounding terrain. The relatively old
crater was filled with sediments in the past, which formed plateaux on
erosion.
The flanks of the plateaux clearly exhibit layering of different-coloured
material. Differences in colour usually indicate changes in the composition
of the material and such layering is called 'bedding'. Bedding structures
are typical of sedimentary rock, which has been deposited either by wind or
water. Different rock layers erode differently, forming terraces.
The valleys exhibit gullies, or channels cut in the ground by running
liquid, mainly in the northern part of the image. These gullies and the
rock-bedding structure indicate that the region has been affected by water.
The sediments in this region are interesting to study because they contain
information on the role of water in the history of the planet. This is one
of the reasons why Terby crater was originally short listed as one of 33
possible landing sites for NASA's Mars Science Laboratory mission, planned
for launch in 2009.
The colour scenes have been derived from the three HRSC colour channels and
the nadir channel. The perspective views have been calculated from the
digital terrain model derived from the HRSC stereo channels. The 3D anaglyph
image was calculated from the nadir channel and one stereo channel,
stereoscopic glasses are required for viewing.
[NOTE: Images supporting this release are available at
http://www.esa.int/esaSC/SEMSEWEMKBF_index_1.html ]