Whipple Observatory: 10-meter Optical Reflector

Mt. Hopkins, Arizona, March 15, 1999

This 10-meter optical reflector, composed of hundreds of hexagonal mirrors, is used to locate sources of high-energy gamma rays to indirectly detect cosmic radiation. A particle striking the upper atmosphere creates a cascade of secondary particles, producing a faint and brief flash of visible light. By tracing the direction of the flash, scientists can identify the source of the gamma rays, such as the Crab Nebula supernova remnant.

By standing at a point directly in front of the reflector, at twice its focal length, I was able to see a 10-meter high reflection of myself, and snap this self-portrait.

The Fred Lawrence Whipple Observatory, located 35 miles south of Tucson, Arizona, is a facility of the Smithsonian Institution Astrophysical Observatory. Public tours of the facilities on Mt. Hopkins, including the 6.5-meter MMT telescope, are available by reservation only. Call (520) 670-5707 for tour information.