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Collection:
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NASA Planetary Photo Journal Collection
Collection
NASA Planetary Photo Journal Collection
Collection
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Title:
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Ripples in Rocks Point to Water
Title
Ripples in Rocks Point to Water
Title
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Original Caption Released with Image:
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This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows the rock nicknamed "Last Chance," which lies within the outcrop near the rover's landing site at Meridiani Planum, Mars. The image provides evidence for a geologic feature known as ripple cross-stratification . At the base of the rock, layers can be seen dipping downward to the right. The bedding that contains these dipping layers is only one to two centimeters (0.4 to 0.8 inches) thick. In the upper right corner of the rock, layers also dip to the right, but exhibit a weak "concave-up" geometry. These two features -- the thin, cross-stratified bedding combined with the possible concave geometry -- suggest small ripples with sinuous crest lines. Although wind can produce ripples, they rarely have sinuous crest lines and never form steep, dipping layers at this small scale. The most probable explanation for these ripples is that they were formed in the presence of moving water.
Crossbedding Evidence for Underwater Origin
Interpretations of cross-lamination patterns presented as clues to this martian rock's origin under flowing water are marked on images taken by the panoramic camera and microscopic imager on NASA's Opportunity.
The red arrows (Figure 1) point to features suggesting cross-lamination within the rock called "Last Chance" taken at a distance of 4.5 meters (15 feet) during Opportunity's 17th sol (February 10, 2004). The inferred sets of fine layers at angles to each other (cross-laminae) are up to 1.4 centimeters (half an inch) thick. For scale, the distance between two vertical cracks in the rock is about 7 centimeters (2.8 inches). The feature indicated by the middle red arrow suggests a pattern called trough cross-lamination, likely produced when flowing water shaped sinuous ripples in underwater sediment and pushed the ripples to migrate in one direction. The direction of the ancient flow would have been either toward or away from the line of sight from this perspective. The lower and upper red arrows point to cross-lamina sets that are consistent with underwater ripples in the sediment having moved in water that was flowing left to right from this perspective.
The yellow arrows (Figure 2) indicate places in the panoramic camera view that correlate with places in the microscope's view of the same rock.
Figure 3
The microscopic view (Figure 3) is a mosaic of some of the 152 microscopic imager frames of "Last Chance" that Opportunity took on sols 39 and 40 (March 3 and 4, 2004).
Figure 4
Figure 4 shows cross-lamination expressed by lines that trend downward from left to right, traced with black lines in the interpretive overlay. These cross-lamination lines are consistent with dipping planes that would have formed surfaces on the down-current side of migrating ripples. Interpretive blue lines indicate boundaries between possible sets of cross-laminae.
Original_Caption_Rel eased_with_Image
This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows the rock nicknamed "Last Chance," which lies within the outcrop near the rover's landing site at Meridiani Planum, Mars. The image provides evidence for a geologic feature known as ripple cross-stratification . At the base of the rock, layers can be seen dipping downward to the right. The bedding that contains these dipping layers is only one to two centimeters (0.4 to 0.8 inches) thick. In the upper right corner of the rock, layers also dip to the right, but exhibit a weak "concave-up" geometry. These two features -- the thin, cross-stratified bedding combined with the possible concave geometry -- suggest small ripples with sinuous crest lines. Although wind can produce ripples, they rarely have sinuous crest lines and never form steep, dipping layers at this small scale. The most probable explanation for these ripples is that they were formed in the presence of moving water.
Crossbedding Evidence for Underwater Origin
Interpretations of cross-lamination patterns presented as clues to this martian rock's origin under flowing water are marked on images taken by the panoramic camera and microscopic imager on NASA's Opportunity.
The red arrows (Figure 1) point to features suggesting cross-lamination within the rock called "Last Chance" taken at a distance of 4.5 meters (15 feet) during Opportunity's 17th sol (February 10, 2004). The inferred sets of fine layers at angles to each other (cross-laminae) are up to 1.4 centimeters (half an inch) thick. For scale, the distance between two vertical cracks in the rock is about 7 centimeters (2.8 inches). The feature indicated by the middle red arrow suggests a pattern called trough cross-lamination, likely produced when flowing water shaped sinuous ripples in underwater sediment and pushed the ripples to migrate in one direction. The direction of the ancient flow would have been either toward or away from the line of sight from this perspective. The lower and upper red arrows point to cross-lamina sets that are consistent with underwater ripples in the sediment having moved in water that was flowing left to right from this perspective.
The yellow arrows (Figure 2) indicate places in the panoramic camera view that correlate with places in the microscope's view of the same rock.
Figure 3
The microscopic view (Figure 3) is a mosaic of some of the 152 microscopic imager frames of "Last Chance" that Opportunity took on sols 39 and 40 (March 3 and 4, 2004).
Figure 4
Figure 4 shows cross-lamination expressed by lines that trend downward from left to right, traced with black lines in the interpretive overlay. These cross-lamination lines are consistent with dipping planes that would have formed surfaces on the down-current side of migrating ripples. Interpretive blue lines indicate boundaries between possible sets of cross-laminae.
Original Caption Released with Image
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Image Credit:
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NASA/JPL/Cornell
Image_Credit
NASA/JPL/Cornell
Image Credit
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Produced By:
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Cornell University
Produced_By
Cornell University
Produced By
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Mission:
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Mars Exploration Rover (MER)
Mission
Mars Exploration Rover (MER)
Mission
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Spacecraft:
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Opportunity
Spacecraft
Opportunity
Spacecraft
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Target Name:
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Mars
Target_Name
Mars
Target Name
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Is a satellite of:
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Sol (our sun)
Is_a_satellite_of
Sol (our sun)
Is a satellite of
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Instrument:
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Panoramic Camera
Instrument
Panoramic Camera
Instrument
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Product Size:
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447 samples x 333 lines
Product_Size
447 samples x 333 lines
Product Size
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facet_what:
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Sun
facet_what
Sun
facet_what
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facet_what:
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Mars
facet_what
Mars
facet_what
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facet_what:
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Opportunity
facet_what
Opportunity
facet_what
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facet_what:
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Imager
facet_what
Imager
facet_what
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facet_what:
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Panoramic Camera
facet_what
Panoramic Camera
facet_what
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facet_what:
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Microscopic Imager
facet_what
Microscopic Imager
facet_what
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facet_what:
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Mars Exploration Rover (MER)
facet_what
Mars Exploration Rover (MER)
facet_what
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facet_where:
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Mars
facet_where
Mars
facet_where
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facet_where:
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Jet Propulsion Laboratory (JPL)
facet_where
Jet Propulsion Laboratory (JPL)
facet_where
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facet_when:
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February 10, 2004
facet_when
February 10, 2004
facet_when
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facet_when_year:
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2004
facet_when_year
2004
facet_when_year
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Image #:
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PIA05482
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UID:
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SPD-PHOTJ-PIA05482
UID
SPD-PHOTJ-PIA05482
UID
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orignial url:
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orignial_url
orignial url
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