The background in the above image, attributed to Arun Kulshreshtha, is a digitally modified rendering of a "color-enhanced version of an aerial photograph of stratocumulus perlucidus clouds taken from the rear seat of a Northwest Airlines Airbus A320 flying over the midwestern United States, en route from Los Angeles, CA to Minneapolis/St. Paul, MN." The original image may be viewed at http://en.wikipedia.org/wiki/File:Above_the_Clouds.jpg. It is licensed under the Creative Commons Attribution 3.0 United States license.