Tyler Nordgren is a professor of physics and astronomy at the University of Redlands, but he's also an artist. He's perhaps best known for his work on a series of WPA poster-influenced public service science pieces. He was also part of the team who designed the MarsDials, which were used on Mars to calibrate the cameras mounted on the Spirit and Opportunity Mars rovers.
Dr. Nordgren is a staunch advocate of the dark night sky, and he explains why we should consider it an endangered resource. He also, like our host Dave Schlom, loves the National Parks.