October 21, 2004

Mars on the big screen

The Visualization Lab at Northwestern offers faculty and students a rare chance to see 3-D images of Mars from NASA’s exploration rovers

By Megan Fellman

A bowl of blueberries by the thousands, a rock called “Lion Stone,” dunes of red sand, the shoreline of a salty sea, wind-sculpted volcanic rock — all of these features of the Martian landscape come to three-dimensional life for faculty and students when they don their 3-D glasses and step into the Visualization Laboratory at Northwestern.

“Mars is not that different from an arid place here on Earth, and we can show that to people with these marvelous stereo images.”

Northwestern is believed to be the only university in the country offering its faculty and students the opportunity to view 3-D images of the red planet from NASA’s two Mars Exploration Rovers (MER), Spirit and Opportunity, as a component to enhance the classroom experience and for research purposes.

Suzan van der Lee, assistant professor of geological sciences, used the Mars images in her Exploration of the Solar System class to discuss the question of whether or not there was water on the rocky planet.

“Everyone had the funny glasses on in the lab, and we were able to view the same images used by NASA scientists to conclude that there was a shallow, salty sea on the surface of Mars,” said van der Lee, who brought 50 undergraduate students to the Vislab in small groups during the winter quarter. “The students were very excited and thought the experience was cool. The 3-D images make Mars more real.”

Scientists from Northwest-ern, the University of Chicago and the Adler Planetarium are bringing these images to the silver screen by taking raw data transmitted daily from the rovers, and, using involved computer programming and processing, turning black-and-white images into full-color 3-D images for academic use.

Northwestern astronomy and geology students, classes visiting from other schools, including Evanston’s Roycemore School, and participants in this year’s Take Your Daughter to Work Day at Northwestern have all been wowed by the spectacular images. (The 3-D images are also available to visitors to the Adler Planetarium & Astronomy Museum.)

When NASA’s Jet Propulsion Laboratory (JPL) launched the rovers last summer, NASA recognized there would be great public interest in the mission. JPL gathered together more than 70 museums and planetariums and formed the Mars Visualization Alliance. The alliance is key in the dissemination of images from the MER mission and in explaining and presenting results of the mission to the public for educational purposes.

“Mars is not that different from an arid place here on Earth, and we can show that to people with these marvelous stereo images,” said Douglas Roberts, manager of the Visualization Lab (Vislab) for information technology at Northwestern and an astronomer with the Adler Planetarium. “Most other members of the alliance are using non-stereo images prepared by NASA for the press because they don’t have the time to create or the technology to project stereo images.”

Roberts arranged for Northwestern to share Mars rover images with the Adler by way of the Visualization Lab and took on the labor-intensive task of manipulating the raw images into a viewable format. Each week Roberts and his colleagues receive data for about 200 images and typically make 50 stereo pictures a week, some in color. (The long-term plan is to create a Web-based library of materials — of the Mars images and other work with which the Vislab is involved — to share with other universities.)

As Roberts explains it, the Mars rovers are equipped with camera “eyes” and other sensors that feed them information about their environment. Two panoramic cameras (Pancams) on each rover image the Martian surface and sky. The Pancam Mast Assembly allows the cameras to rotate a full 360 degrees to obtain a panoramic view of the Martian landscape.

The range of filters on the Pancam detectors allows them to take multispectral images (images taken at various wavelengths). Using a “color wheel” with various filters, the two panoramic cameras create stereoscopic images that are later combined to produce 3-D data. Two navigation cameras (Navcams) mounted on each rover’s “neck and head” also gather panoramic, 3-D imagery, primarily used to navigate the rover on Mars.