December 12, 2004

Burial and exhumation of impact craters, and their destruction by erosion, are common and repeated themes all over the surface of Mars. Many craters in western Arabia Terra exhibit light-toned, layered outcrops of ancient sedimentary rock. Like the sedimentary rocks explored further to the south in Meridiani Planum by the Opportunity Mars Exploration Rover (MER-B), these intracrater sedimentary rocks may have been deposited in water. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example of light-toned sedimentary rocks outcropping in a crater that is much farther north than most of the similar examples in western Arabia. This one shows several old impact craters in various states of erosion and exhumation from beneath and within the sedimentary rock materials. The image is illuminated by sunlight from the lower left.
Exhuming Craters in a Crater - (PIC)

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Redd School Imagines Mars webcast
Watch as students from the Redd School in Houston Texas interview NASA engineers about Mars! Engineers Randy Lindemann and Jessica Collisson will answer questions and share new pictures from the red planet. The Redd School earned this opportunity by becoming November's Project of the Month. Check out their cool project in the gallery.

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7 December 2004
These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, show a region of Reull Vallis in the southern hemisphere of Mars.

The channels of Reull Vallis

why Reull Vallis became his Name

The unusual name "Reull Vallis" is gälischen origin and by vision eras the astronomer and planet researcher Carl Sagan (1931-1996) was suggested, after the valley in pictures of the American Viking probes was discovered. For the Celts of Ireland was "Reull" (expressed: "RH-Ul") the word for planets.

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

December 11, 2004

Today's Mars Picture of the Day features two images. The top picture is a mosaic of Viking orbiter images acquired in the late 1970s. The lower image is a high resolution picture from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The Viking mosaic shows Ceraunius Tholus, a volcano in the Tharsis region that was first viewed in images obtained by Mariner 9 in 1972. Several channels run down the slope of the Ceraunius Tholus volcano. The deepest of those channels ends in an elliptical crater. The elliptical crater was formed by a very oblique meteor impact. Where the channel meets the floor of the elliptical crater, there is a small mound of material. Presumably, this material was deposited in the elliptical crater after running down through the channel on the volcano's northwest flank. Near the top/center of the mound in the elliptical crater is a small, circular depression. Some have speculated for years that this depression is related to volcanism, others thought that it may be an impact crater. The MGS MOC image (lower of the two images) shows that crater. It is not the source of lava flows or any other volcanic features. Most likely, it is an old impact crater. The image is illuminated by sunlight from the lower left.
Ceraunius Tholus Feature - (PIC)

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December 10, 2004

The lower left (southwest) corner of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the location of a somewhat filled and buried meteor impact crater on the northern plains of Mars. The dark dots are boulders. A portion of a similar feature is seen in the upper right (northeast) corner of the image. This picture, showing landforms (including the odd mound north/northeast of the crater) that are typical of the martian northern lowland plains, was obtained as part of the MGS MOC effort to support the search for a landing site for the Phoenix Mars Scout lander. Phoenix will launch in 2007 and land on the northern plains in 2008. The scene is illuminated by sunlight from the lower left.
Northern Plains "Crater" - (PIC)

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December 10, 2004

This Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime IR image is dominated by a large crater. The crater no longer has any visible ejecta, and retains only it's rim - seen here as a varigated black/gray semi-circle surrounding a brighter floor. The smaller craters in the image have bright rings representing their rocky rims. This crater is located just south of Syrtis Major.
Crater At Night - (PIC)

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December 9, 2004

A century ago, the name Percival Lowell and the planet Mars were intimately linked through his popular writings about canals built by intelligent beings on the fourth planet. Today, a crater in the southern hemisphere of Mars is named for Lowell, who usually observed the planet from a hilltop in Flagstaff, Arizona. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, acquired in October 2004, shows a portion of a sand dune field in western Lowell Crater. The image is illuminated by sunlight from the upper left.
Lowell's Dunes - (PIC)

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December 9, 2004

The majority of craters in this Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime IR image appear as bright (warm) rings surrounding dark (cooler) centers. The dark "tails" of the craters are windstreaks. The crater rims are providing a wind-shadow, protecting the dust/fines on the downwind side of the crater. The wind has removed the dust cover from the surroundings, revealing the rockier/ warmer surface. These craters are located in Syrtis Major.
Nighttime Wind Streaks - (PIC)

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December 8, 2004

Yardangs are ridges formed by wind erosion. Most commonly, they will form in sedimentary rocks or volcanic ash deposits containing some amount of sand-sized grains. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of yardangs in the Memnonia Sulci region. The ridges are illuminated by sunlight from the upper left.
Memnonia Sulci Yardangs - (PIC)

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December 8, 2004

The large crater in this Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime IR image had its ejecta emplaced in a semifluidized state, creating an outer rampart at the distal ends of the ejecta blanket. This wall can act as a trap for fine wind blown materials. It is likely that part of the darker/cooler materials surrounding the crater are wind blown materials such as dust and sand. This crater is located north of the Meridiani region of Mars. Note: this THEMIS infrared image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
Dusty Ejecta Blanket - (PIC)

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December 7, 2004

This view from where NASA's Mars Exploration Rover Spirit stood on the rover's 149th martian day shows terrain the rover has crossed since then. The yellow line traces the path Spirit has taken since arriving at the "Columbia Hills." Labels show the informal names of rocks the rover has studied along the way. Spirit is currently headed east, traversing the flanks of the hills en route to an overlook above a steep valley that is out of view from this perspective. Scientists hope to find more layered rocks that will tell a story of ancient water on Mars.
Spirit's Amazing Trek Continues - (PIC)

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December 7, 2004

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows layered outcrops of sediment deposited in southern Chryse Planitia by flow through the Hypanis Valles system in Xanthe Terra. The distinct inverted boat hull-shaped ridges are yardangs formed by wind erosion. The image covers an area approximately 3 km (1.9 mi) wide and is illuminated by sunlight from the left/lower left.
Hypanis Layered Outcrop - (PIC)

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December 7, 2004

The crater in today's Mars Odyssey Thermal Emission Imaging System (THEMIS) image is slightly older than one shown yesterday. The ballistically emplaced ejecta is now a uniform gray tone in this nighttime IR image. With time dust will cover young surfaces and control the IR image tone. This crater is located east of Huygens Crater.
Nighttime IR Ejecta - (PIC)

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December 7, 2004

These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, show a region of Reull Vallis in the southern hemisphere of Mars. This is a view looking south-east across Promethei Terra, back up Reull Vallis and the junction with its tributary, Teviot Vallis.
Channels of Reull Vallis - (PIC)

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December 6, 2004

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an outcrop of light-toned layered rock and a plethora of dark streaks on the floor of a crater in southern Noachis Terra. The streaks were created by dozens of dust devils which disrupted and perhaps removed some of the thin layer of dust that coats the surface. The scene is illuminated by sunlight from the lower right. The 500 meter scale bar is approximately 547 yards long.
Layers and Streaks - (PIC)

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December 6, 2004

This Mars Odyssey Thermal Emission Imaging System (THEMIS) image is of a small crater. Note the bright and dark portions of it's ejecta blanket. With ballistic emplacement of ejecta, larger (heavier) material falls closer to the crater rim than smaller material. This is clearly represented in the nighttime IR, where rockier material is warmer/brighter and finer material is darker/ cooler.
Crater in Nighttime IR - (PIC)

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December 5, 2004

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an exposure of layered material, probably sediment, on the floor of Shalbatana Vallis. Erosion has exhumed small impact craters and created round, layered buttes. The scene is illuminated by sunlight from the lower left.
Layers in Shalbatana Vallis - (PIC)

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December 4, 2004

Exposures of sedimentary rock are quite common on the surface of Mars. Less common, but found in many craters in the regions north and northwest of the giant basin, Hellas, are sedimentary rocks with distinct polygonal cracks in them. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from the floor of an unnamed crater. Such cracks might have formed by desiccation as an ancient lake dried up, or they might be related to ground ice freeze/thaw cycles or some other stresses placed on the original sediment or the rock after it became lithified. The 300 meter scale bar is about 328 yards long. The scene is illuminated by sunlight from the upper left.
Polygon/Cracked Sedimentary Rock - (PIC)

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In many ways, Mars is the most Earth-like of the other planets in our solar system. Learn how scientists can interpret what they see on Mars by following geologist Jim Garvin, Mars lead scientist for NASA, on a virtual tour of Surtsey, a recently formed volcanic island in Iceland.
Mars on Earth - Part I AND Mars on Earth - Part II
(MP4, view with QuickTime or RealPlayer)

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