HD 188753: Triple Sunset . ... Credit Copyright: courtesy JPL-Caltech , NASA Explanation: Although it looks like fiction, this artist's vision of sunset on an alien world is based on fact -- the recent discovery of a hot, jupiter-sized planet orbiting in triple star system HD 188753 . ... While other hot, jupiter-like planets are known to orbit nearby stars, the "crowded" multiple star nature of this system challenges current theories of planet formation . ... U. Based on Astronomy Picture Of the Day ...