Dr. Robert M. Nelson is neither conspiracy theorist nor midnight blogger, but a senior research scientist for NASA and for Caltech’s Jet Propulsion Laboratory, and an international authority on image analysis. Currently he’s engrossed in analyzing digital photos of Saturn’s moon Titan, determining its shape, whether it contains craters or canyons.

On Salon.com, he says imaging techniques prove the president’s bulge was not caused by wrinkled clothing.