... Shuttle Plume Shadow Points to Moon . ... Credit: Pat McCracken, NASA Explanation: Why would the shadow of a space shuttle launch plume point toward the Moon? ... Next, just at sunset, the shadow is the longest and extends all the way to the horizon . Finally, during a Full Moon , the Sun and Moon are on opposite sides of the sky. ... 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. ...