DOTLAN EveMaps

u'"Back in the 60s and 70s, Apollo astronauts circling the Moon saw something that still puzzles researchers today. About 10 seconds before lunar sunrise or lunar sunset, pale luminous streamers would pop up over the gray horizon. These \u201ctwilight rays\u201d were witnessed by crewmembers of Apollo 8, 10, 15 and 17.

Back on Earth, we see twilight rays all the time as shafts of sunlight penetrate evening clouds and haze. The \u201cairless Moon\u201d shouldn\u2019t have such rays, yet the men of Apollo clearly saw them."

NASA Mission To Study Mysterious Lunar Twilight Rays, September 3, 2013'