When is a Planet Not a Planet?: The Story of Pluto/ by Elaine Scott Should Pluto be considered
a full-fledged planet? Scientists have argued for years over the answer to this question, until August 24, 2006, when the International Astronomical Union decided Pluto was no longer a planet. Under new rules, a planet could not cross the orbit of any planetary neighbor. Since Pluto does just that, it was reclassified as a "dwarf planet."
In an attempt to explain how the solar system suddenly went from nine planets to eight, science writer
Elaine Scott delves into the history of the planets orbiting our sun, getting into the specifics about the discovery and subsequent rejection of our formerly ninth planet Pluto.
Scott packs ages of astronomical history into a few easy-to-digest pages. She describes the work of early astronomers, such as Ptolemy, Copernicus and Galileo, and how their discoveries led to the identification and naming of each planet. One of the really interesting chapters is entitled "What is a Planet?" Apparently astronomers around the world had never settled on a definition, but now there are three classes of objects that orbit the sun—planets, dwarf planets, and small solar system bodies.
While perhaps not settling the discussion of Pluto as planet (isn't a dwarf planet still a planet?), Scott does quite satisfactorily secure for her readers an understanding of how and why science evolves and the study of planets in particular. Her easy writing style and clear definition of scientific terms and processes is engaging. .The research is flawless and, although written for young people, adults will also appreciate discovering more about an interesting subject.
The book is illustrated with gorgeous space images, news photos and historical pictures that provide additional information. It really is Beautifully designed from cover to cover.