A fuzzy edge mars gloss

There is a kind of "perfect storm" going on in astronomy. A rapid expansion in our knowledge of the universe, new and startling images of the sky, and big public interest all coincide to make glossy picture books an overwhelming temptation for publishers.

This offering is at the heftier end of the spectrum, with official approval from the Royal Astronomical Society, high production values and a price tag that suggests a library purchase rather than a book to be bought out of one's own income.

But it is competing in a crowded field of direct and indirect rivals. How valuable an addition is it to a growing shelf of popular but serious guides to the sky?

The book is, in fact, a boiled-down version of the four-volume Encyclopedia of Astronomy and Astrophysics, published in 2001, and now supplemented for a popular audience by a clutch of articles on amateur astronomy by experienced practitioners.

The result is a book in which you can find articles on the outer reaches of cosmology alongside beginner-level information on what you can see in the night sky. However, there is confusion in the minds of the editors about the aims of this all-embracing approach. One of the amateur sections is on discovering supernovae, which is like telling someone who has just got their first bicycle to compete in the Tour de France. The authors of the section on photographing meteors have not heard of digital cameras and write about what sort of film to use. There are many other guides to sky-watching, and anyone who wants to get involved would do better to go and buy one than to use the cut-down offering in these pages.

The substantial articles that make up the main text are another story, since they are authoritative and have been updated since the 2001 publication. Astronomy has a broader range of content than most sciences, so the material has to cover everything from asteroid types to supersymmetry. The entries are well written and contain few detectable errors. The same high standard is maintained in the illustrations, which include diagrams as well as images and have been chosen for their information value as well as their capacity to amaze.

Despite these merits, the work has some rough edges. Having approved the book, the Royal Astronomical Society has been left out of its strange list of acronyms and abbreviations in favour of the British Astronomical Association. More seriously, all the sections on planets of the solar system have a box giving their basic characteristics, but the one on Saturn is completely out of style with the others. Most of them give the diameter of the planet, but Neptune's gives the radius. Some give both the polar and the equatorial diameter, others tell you how oblate the planet is and leave you to work it out. Even the basic number for the mean distance of the planet from the Sun is expressed in a variety of ways: astronomical units for all, kilometres for some, and no data for Saturn.

Other decisions are just perverse. Who would look up the W.M. Keck Observatory under "W"? There is no entry on superstrings despite all the attention cosmologists are paying the matter. Entries on cosmology topics such as inflation and supersymmetry are also a little slight, while particles such as the gauge boson get the full treatment. There are 18 references to individual comets, including some that are mainly of historical interest. There is a table of meteor showers but none of the Earth's meteor craters.

There are also many references to individual objects, such as lunar craters or nebulae, which users would be unlikely to find useful. Fewer, longer entries, such as a better one on the fascinating but complex gamma-ray object Geminga, would have been more satisfying and more in keeping with the style of an encyclopaedia rather than an astronomy dictionary. Despite these flaws, the book looks the part and will sell well. But the second edition should be much better.

Martin Ince is contributing editor, The Times Higher .