Astronomy today is a fast-moving science. In particular, our view of the solar system - our home in the universe - is totally different from that of only a few years ago, and every month seems to bring its quota of new discoveries and theories. Many detailed, lavishly illustrated books are being published, and this new offering, by the professor of astronomy at Tufts University in the US, is exceptionally good.
It begins with a short historical prologue taking the reader from ancient times through the telescopic era and on to the space missions of today.
There is a useful section on "generalities", and then the various bodies of the solar system are discussed. The only possible criticism of this arrangement is that there is no separate chapter on the Sun, though the solar-planetary relationships are described all the way through the text.
Two features of the book are especially notable. The text is so clearly written that it is within the scope of even the complete newcomer to astronomy, but there are also sections, usually in boxes, that will be useful to the serious student. The appendix includes a selected list of recent books. The list is reasonably adequate, though inevitably there is almost no reference to material published outside the US.
One insoluble problem facing any author is that some sections of a book are bound to be out of date even on publication day. For example, we know more about Mars now than we did in 2003, from the American rovers Spirit and Opportunity , and the European Mars Express orbiter. The author has dealt with this problem very skilfully, and the text can be further updated for the next edition of the book, which will certainly be required in the reasonably near future.
The survey of the planets and their satellites begins, fittingly, with the Earth - "Third Rock from the Sun" - and here there is a good deal about global warming, about which the author has strong views: "To assess the effects of global warming, one assumes that the dominant cause of climate change during the next century will be the release of greenhouse gases into the atmosphere by humans." Not everyone will agree with this; time will tell, and perhaps the situation is not so clear-cut as might be gathered from what is written here, but the survey of the Earth as a planet is excellent - obviously the author is an expert geologist as well as an astronomer. Next comes the section dealing with the Moon, taking into account the results from post-Apollo missions such as Clementine and Prospector . We have heard a great deal about the possibility of ice on the floors of some of the polar craters, which are always in darkness, and it is suggested that water ice could have been delivered to the Moon by comets, "which are essentially big balls of dirty ice"; the evidence in favour of ice has been weakened since 2003, but the jury is still out. The lunar photographs, mainly from Apollo missions, are excellent, though an outline map of the Earth-turned hemisphere would have been a useful addition for the benefit of the telescope-user.
Space-probe results are again to the fore in the chapter on Mercury and Venus, both of which are as fascinating as they are inhospitable. Much of our knowledge of Mercury comes from the only spacecraft to have flown past the planet ( Mariner 10 , in 1974-75), and we have maps of a large part of the surface, but as is pointed out here, there are marked differences between the mountains and craters of Mercury and those of the Moon. Venus, "the veiled planet", has given up many of its secrets though others remain.
The best maps come courtesy of the US orbiter Magellan , which reached Venus in 1990 and operated for four years. Naming the features is the responsibility of the International Astronomical Union, and all names have to be female. An entertaining list of some of these is given on page 22.
Most people will know about Anna Pavlova and Edith Piaf, but how many people know that Ovda Regio, one of the plains on Venus, commemorates "a violent, ill-tempered spirit who wanders about the Finnish forests naked looking for trespassers to tickle to death"? The Magellan images are well selected and well reproduced.
Only small parts of the Mars chapter need modifying because of recent space missions; all the main problems are discussed with suitable images. The search for any trace of life, past or present, continues, and at least we are sure that running water once existed there, so that Mars used to be more welcoming than it is now. Moreover, the author points out that "living microbes might still be hiding inside the rocks or cores, or we might find fossilised remnants there".
Jupiter and Saturn, the giants of the solar system, have also been studied from spacecraft, and a good selection of images is given, together with the results of current research. The Jovian satellites come in for special attention, with the awe-inspiring volcanoes of Io and the probability of an ocean of liquid water beneath the icy crust of Europa. The chapter on Saturn is also very clear and comprehensive; the pictures from the voyager probes are indeed beautiful, and it is often said that Saturn is the most impressive object in the entire sky. The satellites are discussed in detail, but there are a couple of slips here: Christiaan Huygens discovered only one satellite, Titan, not four (the others were found by G. D.
Cassini), and the author repeats the old myth that when the Sun becomes a red giant star, so that the Earth will become uninhabitable, Titan will perhaps "serve as a haven for interplanetary immigrants". Alas, this will not be possible. Titan will indeed be warmed, but as soon as this happens its atmosphere will escape into space. Mankind can have no refuge there!
Finally we come to the cold outer giants, Uranus and Neptune, and the smaller members of the Sun's family, plus the insubstantial but sometimes spectacular comets. There is a useful chapter dealing with cosmic collisions - were the dinosaurs really wiped out as the result of an asteroid impact? - and appendices that include a directory of websites as well as the bibliography.
This is a well-written and splendidly illustrated book, suitable for readers of all kinds. It may be recommended without hesitation, and will be a welcome addition to any astronomical library.
Sir Patrick Moore has specialised in observations of the Moon, and has been associated with all the main lunar mapping programmes. He has published many books and papers about the Moon and planets.
The Cambridge Guide to the Solar System
Author - Kenneth R. Lang
Publisher - Cambridge University Press
Pages - 452
Price - £30.00
ISBN - 0 521 81306 9