Aram Chaos Sediments
Aram Chaos Sediments
PSP_002839_1825  Science Theme: Sedimentary/Layering Processes
Aram Chaos appears to be a former impact crater. The terrain is disrupted, giving it a chaotic appearance (hence the name “chaos”). Scientists have postulated that a lake may have once existed inside the crater and sediments were laid down within the lake.

The mineral hematite (rich in iron) has been detected by orbiting spacecraft within Aram Chaos. Hematite has been identified in several other locations on Mars, including at the Mars Exploration Rover landing site in Meridiani Planum. The hematite at both Meridiani and Aram Chaos most likely formed by precipitation in water.

This HiRISE image shows the light-toned sediments inside Aram Chaos that could have formed in a former lake. Unfortunately, dark debris now obscures much of this sediment, making it difficult to view and interpret the rocks. The light-toned layered deposit in the south (bottom) of the image is higher standing and has a pitted surface.

Circular structures with dark centers are likely to be impact craters that have been partly filled with dark debris, including sand. More irregular depressions appear to result from erosion of layered beds within the sediments. Wind could erode materials that are slightly weaker more quickly and produce the irregular topography seen along the surface of the deposit.

Written by: Cathy Weitz  (14 March 2007)
Acquisition date
05 March 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
272.3 km (169.2 miles)

Original image scale range
27.2 cm/pixel (with 1 x 1 binning) so objects ~82 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
56°, with the Sun about 34° above the horizon

Solar longitude
194.9°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  355.9°
Black and white
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IRB color
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Merged IRB
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Merged RGB
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IRB color
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Black and white
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non-map           (545MB)

IRB color
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non-map           (432MB)

Merged IRB
map projected  (220MB)

Merged RGB
map-projected  (225MB)

RGB color
non map           (404MB)
B&W label
Color label
Merged IRB label
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EDR products

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RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

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NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA’s Science Mission Directorate, Washington. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.