Postcards from Mars Jim Bell talked about his book, Postcards from Mars: The First Photographer on the Red Planet, published by Dutton. Mr. Bell, an astronomy professor at Cornell University, is the lead scientist for the Mars Exploration Rover’s Pancam color imaging system. He talked about the photographs of Mars taken by two exploration rovers named “Spirit” and “Opportunity.” So far the rovers have taken over 150,000 photos of the planet. Professor Bell, who included over 150 of the photos in his book, showed a sampling of them and discussed what NASA scientists have learned about the geography and geology of the planet since the rovers landed on Mars in early 2004. After his presentation he responded to audience members' questions. close