Jet Approaching a Crescent Moon . ... Credit Copyright: Vincent Jacques Explanation: No natural clouds appear in this picture. ... The contrail would normally appear white, but the large volume of air toward the setting Sun preferentially knocks away blue light , giving the reflected trail a bright orange hue. ... The above image is framed by an eerie gray sky, too close to day to be blue, too close to night to be black. ... The Sun set. ... NASA Web Site Statements, Warnings, and Disclaimers . ...