Galaxies: Immense Star Islands.

The first four books in this fine series focused on the sun, the moon, Earth, and Mars. Each book has the same format: a brief introduction, a table of contents, 12 two-page chapters, two pages of facts and figures, a glossary, a Going Further section (with links to relevant websites), and an index.

Every chapter opens with a question and answer. For example, in Galaxies Chapter 1 asks “What is a galaxy?” and answers: “A galaxy is an enormous group of stars. No two galaxies are exactly the same, but they do have various common shapes.” The rest of the double-page spread contains pictures, illustrations, or composite images; short paragraphs answering more-specific questions (“What size is a galaxy?”, “What shape are most galaxies?”, “What about other shapes?”); and some sidebars, as well as a WOW! section that highlights interesting facts.

The books are filled with fascinating information. Gas Giants, which focuses on Uranus and Neptune, explains such things as the unique rolling pattern of Uranus as it rolls on its side instead of spinning around a vertical axis like the other planets. Hot Planets covers the formation of Mercury and Venus, their moons, gravitational pull, speeds of rotation about their axes and around the sun, atmospheric composition, space missions to the planets, planet surfaces, and weather patterns (these topics are also covered in the other volumes about planets). Ice Dwarfs looks at Trans-Neptunian Objects (the rocky bodies that orbit beyond the planet Neptune), explaining the differences between comets, asteroids, and meteoroids. Mighty Megaplanets answers questions about the rings of Jupiter and Saturn. Spaces Probes describes the technology we’re using to explore our solar system and where we’re going (it features a splendid “view” of the solar system showing nine space probes and their targets). Star Spotters considers the different methods and equipment astronomers use to gather information. The Stars journeys into the Milky Way, explaining to readers how stars are formed, and what constellations, black holes, neutron stars, and supernovas are.

The Young Astronomer section in each book advises on stargazing, though the level of detail is not sufficient to be able to find the objects discussed. The Facts and Figures sections sums up the data presented in the text; in the books about the planets this includes diameter, length of day and year, distance to the sun, surface and atmospheric composition, temperature, and surface gravity (for some reason, the number of moons is only included in Ice Dwarfs). In the Going Further section, some links to astronomy sites designed for kids and to some Canadian sites would have been welcome. Overall, this series provides a good introduction to the solar system. Recommended.