The Lunar Atmosphere and Dust Environment Explorer, orLADEE, is ready for launch! This robotic mission will send an orbiter to the moon to gather detailed information about the lunar atmosphere which very different from our own...as in—almost non-existent. Scientists call it an exosphere because it is so fantastically thin, and they believe these types of atmospheres may be verycommon in the universe. LADEE is also trying to help scientists solve the mystery of the lunar twilight rays—ooh la la their name alone has me intrigued. These are pales, luminous streamers seen by Apollo astronauts a few seconds before the lunar sunrise and sunset. Although common on Earth as sunlight penetrates the cloud and haze, the “airless moon” shouldn’t have these. Scientists hypothesize that dust is being lofted into the thinatmosphere, causing these rays, although they hope LADEE will help to confirm this. But the orbiter is on a timetable. A lunar eclipse to occur next April, which will be a beautiful sight for Earthlings but could be deadly to the solar powered orbiter.