In October 1963, two cartographers with the Air Force Aeronautical Chart and Information Center saw a strange glow on the moon. Using the 24-inch refractor telescope at Lowell observatory in Flagstaff, Arizona, James Greenacre and Edward Barr saw a deep, ruby-red glow coming from the crater Aristarchus. The sighting might have been glowing gas from volcanic activity, and a second sighting in November of that year was verified by Dr. John Hall, Director of the observatory at the time.