NASA's Lunar Atmosphere and Dust Environment Explorer will launch on a mission in August next year to collect data on floating dust particles in the moon's atmosphere. LADEE will investigate the twilight rays several Apollo astronauts saw before lunar sunset and sunrise while orbiting the moon. "If LADEE never sees levitated dust, that settles the question for the high-altitude observations, at least for its mission time frame. ... If LADEE does see dust, we will then have a basis for expecting the same phenomena at all other 'nearly-airless' bodies around the solar system," said LADEE project scientist Rick Elphic of NASA's Ames Research Center in Mountain View, Calif.