This image of the wall of a graben—a depressed block of land between
two parellel faults—in Tyrrhena Terra, in Mars' ancient southern
highlands, was taken by the Compact Reconnaissance Imaging Spectrometer
for Mars (CRISM) at 0914 UTC (4:14 a.m. EST) on February 6, 2008, near
17.3 degrees south latitude, 95.5 degrees east longitude. CRISM's image
was taken in 544 colors covering 0.36-3.92 micrometers, and shows features
as small as 35 meters (115 feet) across. The region covered is just over
10 kilometers (6.2 miles) wide at its narrowest point.
This image was part of an investigation planned by students in four high
schools in Durham, North Carolina. The students are working with the CRISM
science team in a project called the Mars Exploration Student Data Teams
(MESDT), which is part of NASA's Mars Public Engagement Program and
Arizona State University's Mars Education Program. Starting with a
medium-resolution map of the area, taken as part of CRISM's "multispectral
survey" campaign to map Mars in 72 colors at 200 meters (660 feet) per
pixel, the students identified a key rock outcrop to test their hypothesis
that the irregular depression was formed by Martian volcanism. They
provided the coordinates of the target to CRISM's operations team, who
took a high-resolution image of the site. The Context Imager (CTX)
accompanied CRISM with a 6 meter (20 feet) per pixel, high-resolution
image to sharpen the relationship of spectral variations to the underlying
surface structures. The Durham students worked with a mentor on the CRISM
team to analyze the data, and presented their results at the 39th Lunar
and Planetary Science Conference, held in League City, Texas, on March
10-14, 2008.
The upper panel of the image shows the location of the CRISM data and the
surrounding, larger CTX image, overlain on an image mosaic taken by the
Thermal Emission Imaging System (THEMIS) on Mars Odyssey. The mosaic has
been color-coded for elevation using data from the Mars Orbiter Laser
Altimeter (MOLA) instrument on the Mars Global Surveyor (MGS) spacecraft.
Redder colors indicate higher elevations. The bottom left image shows
infrared brightness of the surface measured by CRISM at 2.5, 1.5, and 1.1
micrometers. In the lower right image, the data have been transformed into
a map of spectral features indicating the presence of different minerals.
Redder areas have a stronger signature of the iron-containing mineral
olivine, and green and blue areas show the signature of the mineral
pyroxene.
These data sets, acquired over the last ten years, allow increasingly
detailed and higher-resolution view of Mars' surface that provide
scientists with a variety of measurements to understand Mars' past
evolution. The same data provide teenage amateur geologists a fascinating
and exciting "field site" at which to exercise the principles of earth
science in a real-life, hands-on science investigation.
CRISM is one of six science instruments on NASA's Mars Reconnaissance
Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory,
Laurel, Md., the CRISM team includes expertise from universities,
government agencies and small businesses in the United States and abroad.
NASA's Jet Propulsion Laboratory, a division of the California Institute
of Technology in Pasadena, manages the Mars Reconnaissance Orbiter and the
Mars Science Laboratory for NASA's Science Mission Directorate,
Washington. Lockheed Martin Space Systems, Denver, built the orbiter.