Comet Hale-Bopp, named for its two discoverers Alan Hale and Thomas Bopp,  was photographed at dusk on March 27, 1997, from the 6,100-foot summit of Mt. Laguna in Southern California.  At that time, the comet was at its closest to Earth―about 123 million miles away.  Streaming away from its bright head (the "coma") appears its long, bluish gas tail and its broad, fan-shaped yellowish-white dust tail.  In the lower left corner of the photo lies the tiny elongated glow of M31, the Great Andromeda Galaxy, 2.3 million light years (13.8 million trillion miles) away.  The colorful lights of airplanes bound for San Diego’s Lindbergh Field swirl between the two objects during this 30-minute guided exposure.  Hale-Bopp is also known to astronomers as C1995 O1.