Status Report

Mars Odyssey THEMIS Image: Coprates Chasma

By SpaceRef Editor
May 21, 2002
Filed under , ,


Medium image for 20020521a
Image Context:
Context image for 20020521a
Context image credit: NASA/Mars Orbiter Laser Altimeter (MOLA) Team







The ScienceThe Story
This THEMIS visible image shows the northern interior wall of Coprates Chasma, one of the major canyons that form Valles Marineris. The cliff face seen in this image drops over 8 km from the plateau of Ophir Planum to the north (top) to the floor of Coprates. A complex set of ridges and chutes has been eroded into the layered rock that forms the canyon walls. Streamers of bright and dark material can be seen in many of the chutes, suggesting that loose material (sediment) is moving down the chutes toward the canyon floor. In many places this sediment has completely buried the wall. The uppermost layers near the rim of the canyon are brighter than the lower layers, suggesting that the upper layers are composed of different materials than occur further down the wall. Very few small impact craters can be seen in this image, indicating that the erosion and transport of material down the canyon wall and across the floor is occurring at a relatively rapid rate, so that any craters that form are rapidly buried or eroded.

[Source: ASU THEMIS Science Team]

From the smooth plateau of Ophir Planum (top of image), the dramatic canyon wall of Coprates Chasma falls in chutes and ridges for almost five miles to the dark floor of the canyon, where one lone, brooding impact crater can be seen. It is a rare sight in this part of the canyon, because all of the erosion on the cliff face happens so fast that most craters are rapidly buried or eroded.

You can see how looser material is transported down the canyon by observing all of the bright and dark streaks streaming down the wall. A particularly good example of this continuing descent is in the left-most canyon shoot, where material has tumbled down into its center crevice, gathering in a pile about mid-way down (left-hand side of the image, right at the point where the bright material meets the dark).

A canyon like this one is kind of like a slice through the geologic history of the planet. Each layer in the rock formed at different times, with different materials. You can tell that the bright material in this image is made of different rocks and minerals than the darker layers toward the bottom.

If a lander or a rover ever went to study a Martian canyon up close, a good place to land would be at the bottom. That’s because all of the rock and soil from the top layers are carried down to the bottom. Without needing to climb up the steep canyon wall for a closer look, scientific instruments on the lander or rover would be able to study all the different kinds of materials right there at the bottom and determine what kinds of rock and soil formed through the ages.

Coprates Chasma is one of the major canyons that form Valles Marineris, the largest canyon system in the solar system. If Valles Marineris were on Earth, it would stretch all the way from California to Washington, D.C. Since it also slices a few miles down into the planet’s interior, it’s the perfect place to study the geological history of Mars.

[Questions? Email marsoutreach@jpl.nasa.gov]

[Source: NASA/JPL Mars Outreach]




Note: this THEMIS visual 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.


NASA’s Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA’s Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Image Credit: NASA/JPL/Arizona State University



[ Show Full-Size Image (GIF) ] [ Show Full-Size Image (JPG) ]
[ Show Full-Size Image (PNG) ] [ Show Full-Size Image (TIF) ]











ParameterValue ParameterValue
Latitude-11.9 &nbsp InstrumentVIS
Longitude63.7W (296.3E) &nbsp Resolution (m)19
Image Size (pixels)3043×1235 &nbsp Image Size (km)57.8×23.5

SpaceRef staff editor.