A camera aboard NASA's Mars Odyssey spacecraft has helped develop the most accurate global Martian map ever, the space agency reported. The map, which has since been posted on several Web sites, allows the public to explore and survey the entire surface of the Red Planet. The map, constructed using nearly 21,000 images from the Thermal Emission Imaging System (THEMIS), a multiband infrared camera on Odyssey, has been an 8-year collaborative project between researchers at Arizona State University's Mars Space Flight Facility and NASA's Jet Propulsion Laboratory in Pasadena, Calif.
NASA noted the pictures have been smoothed, matched, blended and cartographically controlled to make a giant mosaic. Users can pan around images and zoom into them, and at full zoom, the smallest surface details are 330 feet wide. The space agency noted that while portions of Mars have been mapped at higher resolution, this map provides the most accurate view so far of the entire planet.
"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, principal investigator for THEMIS and director of the Mars Space Flight Facility. "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."
The Mars Odyssey spacecraft was launched in April 2001 and reached the Red Planet in October 2001; science operations began in February 2002. The mission is managed by JPL for NASA's Science Mission Directorate in Washington, while Lockheed Martin Space Systems in Denver is the prime contractor for the project and built the spacecraft. NASA's Planetary Data System, sponsored by the Science Mission Directorate, archives and distributes scientific data from the agency's planetary missions, astronomical observations, and laboratory measurements.
"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, Odyssey project scientist at 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, while 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.
"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."