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NASA Releases Mosaic of Vast Martian Canyon

15 March 2006

NASA-Google collaboration uses images to produce Google Mars

By Cheryl Pellerin
Washington File Staff Writer

Washington -- A new view of the biggest canyon thus far identified in the solar system merges hundreds of photos from NASA's Mars Odyssey orbiter and gives scientists and the public an online resource for exploring the entire canyon in detail.

The Mars canyon system, Valles Marineris, stretches as far as the distance from California to New York --about 4,500 kilometers -- according to a March 13 NASA press release.

Steep walls nearly as high as Mount Everest (elevation 8,850 meters) give way to many side canyons, possibly carved by water. In places, walls have shed massive landslides that spill far out onto the canyon floor.

"We picked Valles Marineris to make this first mosaic because it's probably the most complex, interesting feature on the entire planet," said geophysicist Phil Christensen, a professor in the Department of Geological Sciences at Arizona State University (ASU).

Christensen is the principal investigator for Mars Odyssey's versatile camera, the Thermal Emission Imaging System (THEMIS).

MARS ODYSSEY’S ODYSSEY

The orbiter launched from Kennedy Space Center in April 2001 and arrived at Mars in October 2001. It spent the next several months achieving a circular mapping orbit by aerobraking (dipping into the atmosphere to slow and shrink the orbit).

The aerobraking concluded in early February 2002, and primary mapping operations began a few weeks later. Mars Odyssey began an extended mission in August 2004 after completing its primary mission.

"To understand many of the processes on Mars – erosion, landsliding and the effects of water – you really need to have a big-picture view but still be able to see the details,” Christensen said.

THEMIS began observing the planet systematically in February 2002 in visible wavelengths and in infrared wavelengths, which are better for seeing surface details through Mars' atmospheric dust.

As the spacecraft passes over an area, the camera records images of swaths 32 kilometers wide. More than three years of observations made at infrared wavelengths during Martian daytime are combined into the assembled view of Valles Marineris.

Small parts of the canyon have been seen at higher resolution, but at 100 meters per pixel, the new view has sharper resolution than any previous imaging of the entire canyon.

In addition to the mosaic of Valles Marineris images, the camera team also prepared an online data set of nearly the entire planet of Mars at 232 meters per pixel, the most detailed global view of the Red Planet.

The team plans to post 100-meter-resolution mosaics of other regions of Mars in coming months.

GOOGLE MARS

To make the images more available to the public, the ASU team collaborated with online search company Google to produce Google Mars, a Web site that uses NASA imagery to let anyone who has a computer explore Mars.

At the heart of Google Mars is a gigantic mosaic image of Mars. The mosaic uses more than 17,000 individual infrared photos from THEMIS at a scale that resolves features as small as 230 meters across.

Embedded in Google Mars is the Valles Marineris image. Researchers at the Mars Space Flight Facility built the mosaic image from more than 500 separate photos that show landscape features only 100 meters across.

“The Valles Marineris mosaic led naturally to another project of ours,” the team says on its Web site, “carried out in collaboration with a team from the [NASA] Jet Propulsion Laboratory's Digital Image Animation Laboratory.”

The result was Flight Into Mariner Valley, a computer-animated movie that takes viewers on a simulated flight through Valles Marineris.

For additional information, see Google Mars or THEMIS on the Arizona State University Web site.

(The Washington File is a product of the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)