WHEN IS A PLANET NOT A PLANET?

Joining the rush of revised views of the solar system for young readers that has been following in the wake of the International Astronomical Union’s decision to redefine Pluto (and some other fellow wanderers) as “dwarf planets” rather than the full-fledged sort, this production shows several signs of haste, from a narrative that fails to note that Pluto has more than one moon to a chapter that opens with a full page, uncaptioned photo of a vague smear of light. Scott launches into a clear, simply phrased but standard and mostly off-topic history of astronomy and the discovery of our solar system. Aside from that blur, the accompanying space photos, diagrams, artists’ conceptions and art reproductions are up to this author’s and publisher’s usual high quality, but as more focused, considered treatments of the topic are already available or likely to be coming soon, don’t rush to buy this one. (index, reading list) (Nonfiction. 9-11)