Cause of Lunar Twilight Rays Seen by Apollo Astronauts to Be Investigated by LADEE Mission

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 “twilight rays” 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 “airless Moon” shouldn’t have such rays, yet the men of Apollo clearly saw them.

Later this week a NASA spacecraft is going back to the Moon to investigate. Slated for launch on Sept 6, 2013, the Lunar Atmosphere and Dust Environment Explorer (“LADEE” for short) will seek out twilight rays and other mysteries of the lunar atmosphere.

The rest of this story is over at MoonFacts.net

Filed under: The Moon