July 26, 2010
A camera aboard NASA's Mars Odyssey spacecraft has helped develop the most accurate global martian map ever. Researchers and the public can access the map via several websites and explore and survey the entire surface of the Red Planet.
Scientists constructed the map using nearly 21,000 images from the Thermal Emission Imaging System (THEMIS), a multiband infrared camera on Odyssey. Researchers at Arizona State University's Mars Space Flight Facility in Tempe, in collaboration with NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, have been compiling the map since THEMIS observations began 8 years ago.
The pictures have been smoothed, matched, blended, and cartographically controlled to make a giant mosaic. Users can pan around images and zoom into them. At full zoom, the smallest surface details are 330 feet (100 meters) wide. While portions of Mars have been mapped at higher resolution, this map provides the most accurate view so far of the entire planet.
The new map is available at: http://www.mars.asu.edu/maps/?layer=thm_dayir_100m_v11
Advanced users with large-bandwidth, powerful computers and software capable of handling images in the gigabyte range can download the full-resolution map in sections at: http:// www.mars.asu.edu/data/thm_dir_100m
"We've tied the images to the cartographic control grid provided by the U.S. Geological Survey, which also modeled the THEMIS camera's optics," said Philip Christensen from the Mars Space Flight Facility at Arizona State University. "This approach lets us remove all instrument distortion, so features on the ground are correctly located to within a few pixels and provide the best global map of Mars to date."
Working with THEMIS images from the new map, the public can contribute to Mars exploration by aligning the images to within a pixel's accuracy at NASA's "Be A Martian" website, which was developed in cooperation with Microsoft Corp. Users can visit the site at: http:// beamartian.jpl.nasa.gov/maproom#/MapMars
"The Mars Odyssey THEMIS team has assembled a spectacular product that will be the base map for Mars researchers for many years to come," said Jeffrey Plaut from JPL. "The map lays the framework for global studies of properties such as the mineral composition and physical nature of the surface materials."
Other sites build upon the base map. At Mars Image Explorer, which includes images from every Mars orbital mission since the mid-1970s, users can search for images using a map of Mars at: http://themis.asu.edu/maps
"The broad purpose underlying all these sites is to make Mars exploration easy and engaging for everyone," Christensen said. "We are trying to create a user-friendly interface between the public and NASA's Planetary Data System, which does a terrific job of collecting, validating, and archiving data."