Martin Ince casts an eye over the Moon to see what the fuss is about.
Patrick Moore knows the Moon better than most people know the Earth. His latest book on the subject is the product of some six decades of thinking and reading about it and, most important, examining it - either through the eyepiece of the telescope or indirectly. He has even discovered a lunar impact basin, the Mare Orientale, which is on the Moon's invisible far side but of which hints can sometimes be seen from the Earth.
The combination of Moore's expert knowledge and his distinctive style are irresistible. He has a strong sense of the Moon being a world in its own right, not just an appendage to the Earth, as shown by his 57-page appendix describing the near side visible from Earth. Even this only scratches the surface of his expertise. For he also has a keen awareness of the stages of human exploration of the Moon, marked by the invention of the telescope, the arrival of photography and the dawn of the space age.
Telescopes allowed the Moon to be viewed with accuracy for the first time and brought in their wake names for its features and systematic theories of their origin. Photography did not replace drawing as a means of recording the Moon, but its reproducibility put lunar studies on a scientific footing. And the coming of the space age meant that moon rock could be analysed and dated; the Moon's atmosphere, earthquakes and magnetic fields could be thoroughly investigated; and its far side could be viewed.
Formed by the collision of a Mars-sized object with the early Earth, the Moon is a showcase of astronomical history. Its existence means that we are able to sit on the Earth, with its environment uniquely habitable for our species, and conduct solar-system studies in a handy laboratory close by in astronomical terms.
Moore talks systematically about the Moon's origin, its interactions with the Earth and its inner structure. But he is at his best when he writes about human attitudes to the Moon, such as eccentric Nazi theories about a future Earth-Moon collision. Despite the growth in our scientific knowledge, many people are still inclined to hold bizarre lunar theories. Some claim to have seen lunar inhabitants, others believe that Nasa faked the Apollo moon landings. Moore writes about these and many other lunacies with insight and humour.
He has to wrestle in his book with the fact that human landings on the Moon - a high point in 20th-century history and in the author's own life - ended three decades ago, before some of his intended readers were born. Sensibly he restricts the space he devotes to the technical feats of the 1960s and early 1970s and to human exploration of the Moon in general, although there is a final chapter on a possible future Moon settlement. His real interest is in the Moon itself, not in the machines we have built to disturb it.
As well as being a good read, the book is useful, with a clutch of appendices on everything from lunar eclipses to "successful lunar missions" (where the definition is stretched to breaking point by the inclusion of Apollo 13 ). I have a few quibbles, such as Moore's explanation of why meteorites are comparatively easy to find in areas of the Antarctic, but there are no serious flaws.
Sir Patrick never went to university, except to pick up honorary degrees. By contrast, David Whitehouse has a PhD in astronomy, so it is odd that Whitehouse's book about the Moon in some ways contains less science than Moore's. He devotes far more space to different cultures' lunar ideas, and to oddities such as links between the Moon and human behaviour, or gardeners' beliefs in the efficacy of planting at the right phase of the Moon. Some of the history is fascinating. For example, Whitehouse points out that Plutarch, who died in about AD 120, named the prominent features of the Moon long before Galileo saw them through a telescope. But he does not make the obvious point that Plutarch must therefore have realised that the Moon keeps the same face turned to the Earth. Nor does he mention the ancient theory that the Moon is a mirror whose markings are a reflection of the Mediterranean regions of the Earth. And the fact that our ancestors had practical reasons to be interested in the Moon - it raises tides and lights up the night - figures far less than its apparently ritual connotations in his account.
Whitehouse, like Moore, is a Moon enthusiast who gets a thrill from seeing the Moon at close telescopic quarters. The best thing in the book is chapter two, in which he lovingly describes the Moon's changing face as its illumination alters over the course of a month. He is also better than Moore on the Moon's origin and its subsequent history of meteorite impact and internal activity. By contrast, his lengthy coverage of the now-hoary Soviet-United States space race has little new to offer and ought to have been cut back, despite his knowledge of and enthusiasm for the technology of space exploration.
But he is right to point out that the future of human exploration and use of the Moon is a conundrum. The knowledge acquired in sending people to the Moon has died out, in an almost unique twist in the history of technology. Despite some successful Moon missions in the 1990s, notably the US Clementine satellite, plans for humans to return to the Moon are tentative and lack economic and scientific rationale.
In the 1970s, the Moon seemed a promising source of raw material for the exploration of the solar system. Its low gravity makes it easier to get Moon material than Earth matter into space. But asteroids are an even lower-gravity reserve of much the same resources. And negative or inconclusive searches for water suggest that everything needed for life - apart from some dust that might be used as soil - is missing from the Moon. As Moore points out, it lacks the acid clouds, volcanoes and howling gales of some other corners of the solar system. Instead it offers an airless desert, alternately baked and frozen.
Whitehouse believes in the idea of lunar settlement. But his idea that a moon base could pay for itself by solving the terrestrial energy crisis through the mining of raw materials for fusion reactors must be charitably regarded as a long shot. Although he looks at a variety of other proposals, few seem compelling. Orbiting space stations, and longer-term trips to more appealing destinations such as Mars, leave little financial or scientific room for new lunar ventures.
No matter. For Moore, Whitehouse and many others, the Moon will continue to be the most gripping object in the night sky. Both of these books articulate their authors' fascination with the Moon and will succeed in their purpose if they persuade more people to take a look at it for themselves.
Martin Ince is deputy editor, The THES .
The Moon: A Biography
Author - David Whitehouse
ISBN - 0 7472 7228 X
Publisher - Headline
Price - £14.99
Pages - 320