TEN WORLDS

With breathtaking, beautifully reproduced images from NASA, astronomer Croswell introduces the newest version of our solar system. Double-page spreads, or more, are devoted to the general solar system, the sun, each of the ten planets, comets, meteors and the system’s birth. The tone is informal, but the text includes a wealth of information, appropriate comparisons and good transitions; many words are defined in context. The backmatter includes charts comparing the ten planets, seven big moons and first four asteroids, a list of planetary extremes and an index but no glossary. Science writing for young readers often involves presenting generally accepted information as facts, but Croswell has taken some chances here. For instance, the International Astronomical Union will not even decide if 2003 UB313 is a planet until this summer. He does mention the controversy, but, except for the careful book title, treats its acceptance as established fact. Hindsight will show whether this and other choices were right or wrong. For now, teachers and middle-grade readers will welcome this informative visual feast. (Nonfiction. 8-14)