Dr. Stephen P. Maran spent more than 35 years in NASA, working on the Hubble Space Telescope and other scientific projects, and is the press officer for the American Astronomical Society. His 10 previous books include Astronomy for Dummies® and The Astronomy and Astrophysics Encyclopedia. His awards and honors include the naming of an asteroid for him by the International Astronomical Union, the NASA Medal for Exceptional Achievement, the American Astronomical Society's George Van Biesbroeck Prize, and the Astronomical Society of the Pacific's Klumpke-Roberts Award for outstanding contributions to the public understanding and appreciation of astronomy. Residence: Chevy Chase, MD.

Laurence A. Marschall is the WKT Sahm Professor of Physics at Gettysburg College and the author of The Supernova Story. He is a regular columnist for Natural History, a contributing editor of Smithsonian Air and Space, and an astronomy contributor for The World Book Encyclopedia. He is the deputy press officer of the American Astronomical Society and has been published in numerous publications, including Astronomy, Discover, Harper's, Newsday, and The New York Times Book Review. He lives in Gettysburg, PA.