Scott takes the 2006 downgrading of Pluto from planet to dwarf planet as a teachable moment for discussing questions such as how the number of planets has changed through the centuries, what can be called a planet, and how scientists come to conclusionsand occasionally change their minds. Following a section on early astronomy, a succinct, timely, and somewhat surprising account of planetary history begins with Herschel's 1781 discovery of the seventh planet, Uranus. Twenty years later, Piazzi found Ceres, which was considered the eighth planet. In 1846, Galle discovered Neptune, bringing the total to nine. When objects similar to Ceres were found in the same orbit, all (including Ceres) were placed in a new category: asteroids. In other words, even before the discovery of Pluto, there were once nine planets, but one of them was demoted. Beautifully designed, the book includes many well-captioned, color illustrations, from period portraits to NASA images to artist's conceptions. A glossary and lists of recommended books and Web sites are appended. A good choice for updating astronomy collections. Phelan, Carolyn
"Through engaging and child-friendly language, Scott discusses the history ... behind the discovery of the nine planets.... A great resource." School Library Journal, Starred
"Beautifully designed.... A good choice for updating astronomy collections." Booklist, ALA
Illustrations include photographs of astronomers and outer space; artists' renderings of simulations, such as a protoplanetary disk forming around a star; and diagrams of various planetary features. A glossary, recommended readings and websites, and an index round out the book.
Color photos and diagrams are both attractive and informative, and slightly oversized fonts makes the subject seem less daunting.
Bulletin of the Center for Children's Books
"This is a great example to show students the power of research...an outstanding title." LMC January 2008 Library Media Connection