When the International Astronomical Union adopted a new definition of a "planet" in August 2006, Pluto became a dwarf planet, drawing a divisive line in science and public opinions. The controversy of whether Pluto is a planet continues years later, and passion about the decision remains, pitting scientist against scientist and invoking sentiments and nostalgia from the rest of the world. With the IAU definition, the future of space objects is forever changed. Learn how this resolution came to be and what it means for astronomy, who implemented it and who is against it, and whether it's the first or millionth time the world's view of astronomy has rotated on its axis. Written by an astronomer and educator who voted for the IAU resolution--Laurence A. Marschall--and a NASA scientist who supported the opposing petition that resulted--Stephen P. Maran--Pluto Confidential leaves no perspective out and no asteroid unturned in the Pluto debate. A telescopic look inside the book: * History of planetary disputes, including why Jupiter almost wasn't acknowledged * What Bode's Law is and how it has influenced observations * Who discovered Pluto and how it was named * The Kuiper Belt and its role in what it means to be a planet * Beyond Pluto and the eight distinguished planets

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, PhD, is the WKT Sahm Professor of Physics at Gettysburg College where he teaches courses in astronomy, physics, and science writing. He received his bachelor's degree at Cornell University and his doctorate at University of Chicago. He writes a regular column on science books of note for Natural History magazine, is a contributing editor of Smithsonian Air and Space, and contributes annual astronomy updates to The World Book Encyclopedia. He serves as deputy press officer of the American Astronomical Society. In addition to more than 40 articles in professional journals, Marschall has written for publications such as Sky and Telescope, Astronomy, Natural History, Discover, Harper's, Newsday, and The New York Times Book Review. Residence: Gettysburg, PA.