by bystander » Wed Apr 27, 2011 9:18 pm
HiRISE Science Team wrote:Shapes and Gullies (ESP_021491_1440)
This observation shows a well-preserved impact crater on the rim of a
much larger crater located in Terra Cimmeria, in the Southern highland region of Mars.
This crater, like many others on Mars, has several gullies which can you see in the
subimage. Gullies often occur on steep slopes and on crater walls, although their origin is still a point of ongoing investigation.
Another interesting aspect of this observation is the shape of the terrain near the center of the crater floor.
HiRISE Science Team wrote:Rhythmic Stratigraphy (ESP_021523_1825)
This observation represents a particularly good exposure of rhythmic stratigraphy within a crater in southern Arabia Terra, which was previously imaged by the Mars Orbiter Camera.
Measurements of the bedding from stereo topography will help test for the presence of cyclicity, as well as evaluate regional stratigraphic correlations. One of the justifications for this target was to obtain finer scale stereo topography, and HiRISE has created an
anaglyph image of this observation. This will hopefully resolve the exposed bedding at this location. Additionally, stereo topography will help to derive true stratigraphic thicknesses and bedding orientations.
Nicole Baugh wrote:Lots of Layers in Terby Crater (ESP_021942_1520)
Erosion has revealed many sedimentary rock layers in this image in Terby Crater. Terby, a 170 kilometer (approximately 100 mile) crater along the northern edge of Hellas Planitia, is interesting to scientists because of its apparent modification by liquid water. Sedimentary rocks like those revealed in the plateaus of this image can be emplaced by both wind and water. Erosional features in Terby give us an enticing view into the layers and may contain clues as to whether water once flowed across the surface.
The enhanced-color
subimage shows several gully-like features that cut across multiple sedimentary layers. (Up is to the left in this image.) Eroded material has been deposited in fans at the base of the plateau (lower right). The gully incisions reveal a fresher view (slightly bluish or purplish) of the layers making up the plateau than the uncut layers (brownish). There is a change in color (to a lighter, yellower tone) of the layers at the very top of the gully alcove (left) and the surface there becomes smoother and less steep. ...
Credit: NASA/JPL/University of Arizona
<< Previous HiRISE thread[quote="HiRISE Science Team"][float=left][img3=""]http://www.uahirise.org/images/wallpaper/800/ESP_021491_1440.jpg[/img3][/float][url=http://www.uahirise.org/ESP_021491_1440][b][i]Shapes and Gullies (ESP_021491_1440)[/i][/b][/url]
This observation shows a well-preserved impact crater on the rim of a [url=http://www.uahirise.org/ESP_016810_1435][b]much larger crater[/b][/url] located in Terra Cimmeria, in the Southern highland region of Mars.
This crater, like many others on Mars, has several gullies which can you see in the [url=http://www.uahirise.org/images/2011/details/cut/ESP_021491_1440_cut.jpg][b]subimage[/b][/url]. Gullies often occur on steep slopes and on crater walls, although their origin is still a point of ongoing investigation.
Another interesting aspect of this observation is the shape of the terrain near the center of the crater floor.[/quote]
[quote="HiRISE Science Team"][float=left][img3=""]http://www.uahirise.org/images/wallpaper/800/ESP_021523_1825.jpg[/img3][/float][url=http://www.uahirise.org/ESP_021523_1825][b][i]Rhythmic Stratigraphy (ESP_021523_1825)[/i][/b][/url]
This observation represents a particularly good exposure of rhythmic stratigraphy within a crater in southern Arabia Terra, which was previously imaged by the Mars Orbiter Camera.
Measurements of the bedding from stereo topography will help test for the presence of cyclicity, as well as evaluate regional stratigraphic correlations. One of the justifications for this target was to obtain finer scale stereo topography, and HiRISE has created an [url=http://www.uahirise.org/anaglyph/singula.php?ID=ESP_021523_1825][b]anaglyph image[/b][/url] of this observation. This will hopefully resolve the exposed bedding at this location. Additionally, stereo topography will help to derive true stratigraphic thicknesses and bedding orientations.[/quote]
[quote="Nicole Baugh"][float=left][img3=""]http://www.uahirise.org/images/wallpaper/800/ESP_021942_1520.jpg[/img3][/float][url=http://www.uahirise.org/ESP_021942_1520][b][i]Lots of Layers in Terby Crater (ESP_021942_1520)[/i][/b][/url]
Erosion has revealed many sedimentary rock layers in this image in Terby Crater. Terby, a 170 kilometer (approximately 100 mile) crater along the northern edge of Hellas Planitia, is interesting to scientists because of its apparent modification by liquid water. Sedimentary rocks like those revealed in the plateaus of this image can be emplaced by both wind and water. Erosional features in Terby give us an enticing view into the layers and may contain clues as to whether water once flowed across the surface.
The enhanced-color [url=http://www.uahirise.org/images/2011/details/cut/ESP_021942_1520_cut.jpg][b]subimage[/b][/url] shows several gully-like features that cut across multiple sedimentary layers. (Up is to the left in this image.) Eroded material has been deposited in fans at the base of the plateau (lower right). The gully incisions reveal a fresher view (slightly bluish or purplish) of the layers making up the plateau than the uncut layers (brownish). There is a change in color (to a lighter, yellower tone) of the layers at the very top of the gully alcove (left) and the surface there becomes smoother and less steep. ... [/quote]
[b][i]Credit: NASA/JPL/University of Arizona[/i][/b]
[url=http://asterisk.apod.com/viewtopic.php?f=29&t=23436][size=85][b][i]<< Previous HiRISE thread[/i][/b][/size][/url]