In January 1969, astronomers at Steward Observatory were the first to detect the optical flash from a pulsar, observing the Crab pulsar with a photon-counting detector. In January 2019, near the 50th anniversary of this discovery, Steward astronomers, testing a new high-speed imaging camera at the MMT, observed the Crab pulsar, taking images 194 times per second. This video shows the flash in visible light of the Crab Nebula pulsar, a rapidly rotating neutron star that is the collapsed remnant of a supernova. This video shows the pulsar additionally processed. The flash occurs when the pulsar beam passes across our line of sight, like a lighthouse beam. Credits: Eric Pearce, Shane Walsh, Benjamin Weiner, Harry Krantz, Adam Block.