Razorback Mystery

While Opportunity descends the steep walls of Endurance Crater, it continues to add to its portfolio of evidence on martian water history. One current mystery entails pointed rocks lined up. The tiny protrusions have been dubbed, the razorbacks. Based on a geologist’s picture of what forms similar structures on Earth, as a brine deposits minerals of varying hardness, eventual erosion cuts away segments preferentially to form spikes and aligned channel guides.


 

squyresThe panoramic camera on NASA’s Mars Exploration Rover Opportunity produced this approximate true-color mosaic image from a position at the edge of "Endurance Crater." The image shows the "Karatepe" ingress, where the rover began its traverse down into the crater on sol 159 (July 5, 2004). The rover is currently about 10 meters (32.8 feet) into the crater. One of the major goals motivating the rover team to carefully drive the rover further down into the crater is to follow up on clues observed so far involving the element chlorine and the mineral pyroxene. The rover has found that chlorine and pyroxene (a signature of basaltic, or volcanic, rocks) increase in concentration with deepening layers of rock. Scientists also hope to study the dunes, or "ripples," visible at the bottom right of this image. These dunes show strong signatures for basalt and could further develop the history of this area of Meridiani Planum. Credit: NASA/JPL

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The darker blue line in this approximate true-color mosaic from the panoramic camera on NASA’s Mars Exploration Rover Opportunity shows the rover’s position as of sol 170 (July 16, 2004). The rover is located at the end of the blue portion of the line, about 10 meters (32.8 feet) into "Endurance Crater." The rover took this image while sitting on the opposite edge of the crater. The image also shows the "Karatepe" ingress, where the rover began its traverse down into "Endurance Crater" on sol 159 (July 5, 2004). One of the major goals motivating the rover team to carefully drive the rover further down into the crater is to follow up on clues observed so far involving the element chlorine and the mineral pyroxene. The rover has found that chlorine and pyroxene (a signature of basaltic, or volcanic, rocks) increase in concentration with deepening layers of rock. Scientists also hope to study the dunes, or "ripples," visible at the bottom right of this image. These dunes show strong signatures for basalt and could further develop the history of this area of Meridiani Planum. Credit: NASA/JPLsquyres
squyresThis plot shows that levels of the element chlorine rise dramatically in the deeper rocks lining the walls of the crater dubbed "Endurance." The data shown here were taken by the Mars Exploration Rover Opportunity’s alpha particle X-ray spectrometer at Endurance and "Eagle Crater," the site where Opportunity first landed at Meridiani Planum. Opportunity has been inching down the walls of Endurance Crater, investigating distinct layers of rock as it goes for clues to Mars’ buried past. The various Endurance layers have been informally labeled "A" through "F." Targets within these layers are listed on the graph along with previous targets from Eagle Crater. All the rocks listed here were observed after they had been drilled by the rover’s rock abrasion tool. The observations indicate that the elements making up the shallow rock layers of Endurance Crater resemble those of Eagle, while the deeper layers of Endurance possess increasingly higher concentrations of the element chlorine. Credit: NASA/JPL
The pointy features in this image may only be a few centimeters high and less than 1 centimeter (0.4 inches) wide, but they generate major scientific interest. Dubbed "Razorback," this chunk of rock sticks up at the edge of flat rocks in "Endurance Crater." Based on their understanding of processes on Earth, scientists believe these features may have formed when fluids migrated through fractures, depositing minerals. Fracture-filling minerals would have formed veins composed of a harder material that eroded more slowly than the rock slabs. Possible examination of these features using the instruments on NASA’s Mars Exploration Rover Opportunity may further explain what these features have to do with the history of water on Mars. This false-color image was taken by the rover’s panoramic camera. Credit: NASA/JPL

See Opportunity image gallery and slideshow

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MER flight planning chronicled in the diary of the principal investigator for the science packages, Dr. Steven Squyres: Parts 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 .

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