Though the number of celestial objects regarded as planets has varied through the centuries, the rate of change has dramatically increased. Only three years after the publication of 11 Planets: A New View of the Solar System (2008), Aguilar offers an amended volume reflecting the findings of the International Astronomical Union, which currently classifies eight objects in the solar system as planets and, with the addition of Haumea and Makemake, five as dwarf planets. Although a great deal of the material is familiar from the previous book, Aguilar has not only added sections on Haumea and Makemake, he has also used this opportunity to rewrite portions of the text and captions throughout the book and, in some cases, to substitute new illustrations or improve old ones for the new volume. The result is a more readable, more accurate, and more handsome edition of the previous work.

In this useful volume, Aguilar explains the latest categorizations of planets in the solar system (currently considered to be eight planets and five dwarf planets), then profiles each, along with providing information about the sun and various other nearby bodies. Most of the crisp illustrations are color-enhanced photographic images or digital-looking artistic renderings. Basic planet stats are appended. Websites. Glos., ind.

Gr 4-6 Including remote Eris, Haumea, and Makemake in his count of major and dwarf planets, Aguilar tours the solar system from the Sun out to the Oort Cloud, highlighting such relatively recent discoveries as Saturn's "dark ring" and closing with a quick note about extrasolar planets. A claim that "occasionally a colossal meteorite strikes the Earth" seems likely to provoke unnecessary anxiety, and readers will struggle to draw anything meaningful from the statement that "billions of years from now, as our Sun begins its final days, new worlds among the stars may await our arrival." Furthermore, both Mercury and Jupiter's moon Callisto are designated as "the most heavily cratered object in our solar system," and recent observations have cast doubt on whether Eris is actually larger than Pluto, as claimed here. Alongside the volume's many excellent, large, sharply detailed space photos and paintings are provocatively posed smaller images of often scantily clad gods and goddesses representing their eponymous planets, which strike a dissonant note. Though the continuing flood of new knowledge about our solar neighborhood makes frequent updates a necessity, this one is problematic. John Peters, formerly at New York Public Library