Tuesday, September 18, 2007

Best Views of Planet Mars Now Online


Anyone connected by Internet can now see planet Mars better than at any time in history, through the eye of HiRISE, the most powerful camera ever to orbit another planet.

A University of Arizona-based team that runs the High Resolution Imaging Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter has just released more than 1,200 Mars images to the Planetary Data System, the U.S. space agency's mission data archive.

Not only has the team released 1.7 Terabytes of HiRISE data -- the largest single dataset ever delivered to NASA's space mission data library -- but also a user-friendly way for the public to easily see HiRISE images.

Thanks to tools available on HiRISE's any Internet user can quickly pull up and explore the same remarkable images that both thrill and confound scientists.

These images must contain hundreds of important discoveries about Mars, We just need time to realize what they are.

The HiRISE camera takes images of 3.5-mile-wide (6 km) swaths as the orbiter flies at about 7,800 mph between 155 and 196 miles (250 to 316 km) above Mars' surface. For at least the next 18 months, HiRISE will collect thousands of color, black-and-white and stereo images of the Martian surface, resolving features as small as 40 inches across, covering about one percent of the planet.

The team based at UA's HiRISE Operations Center began releasing selected images on the Internet when science operations began in November 2006. Team members began reprocessing all the images taken up to March 25, 2007, using improved calibration, or image correction techniques, in April.

HiRISE Web site gives general users, as well as scientists, a tool to quickly home in on any location within a single huge HiRISE image, which often will be a gigabyte image measuring 20,000 pixels by 50,000 pixels. The tool, which was developed by ITT-Visual Information Solutions in Boulder, is called the IAS Viewer. Users can download it for free directly from the HiRISE Website.

The advantage to IAS-Viewer technology is that it transmits only the amount of data needed to render that portion of the image displayed on the computer screen. That is, each time a user zooms in on a image, he or she doesn't download a completely new set of pixels. Instead, the user is downloading only the higher resolution parts of the image data, which are added to the image data already downloaded by the viewer. The IAS Viewer ultimately renders the selected part of the image in high resolution by adding more and more pixels.