The Technique high-energy gamma-rays hit upper atmosphere Collisions w/ molecules make particle showers particles generate Cerenkov light collect Cerenkov light at ground reconstruct shower/ incoming photon	The Whipple Telescope: 10 meter light bucket located on Mt. Hopkins in Arizona fast electronics = phototube "camera" Next step: VERITAS an array of Whipple clones higher positional accuracy + sensitivity
Science the Crab nebula and supernova remnants Active Galaxies flux, time variability, imaging, and spectroscopy