Shuttle Plume Shadow Points to Moon . ... Credit Copyright: NASA . ... Next, just at sunset, the shadow is the longest and extends all the way to the horizon . ... Just after sunset , for example, the Sun is slightly below the horizon , and, in the other direction, the Moon is slightly above the horizon . Therefore, as Atlantis blasted off, just after sunset , its shadow projected away from the Sun toward the opposite horizon, where the Full Moon just happened to be. ... NASA Official: Jay Norris. ...