The spacious firmament on high
Andro Linklater
THE PLANETS by Dava Sobel Fourth Estate, £15, pp. 271, ISBN 1857028503 ✆ £12 (plus £2.45 p&p) 0870 429 6655 This is the most dazzling era in astronomy that human history has ever known, but for all the attention it commands it could be the dullest. It seems almost routine, a swiftly forgotten news item at best, to see images of Mars beamed back from the planet’s surface or to have a comet’s content analysed by fragmenting its surface with a rocket. The astonishing construction of a space station circling the earth is of such little interest, it is wholly obscured by anxieties about the Shuttle that serves it. The seven-year, 2.2billion-mile, inch-perfect flight of the Cassini spacecraft to examine Saturn’s moons registers only slightly more than the discovery this summer of 30 million new stars in the Milky Way by the Spitzer infrared space telescope. Compared with what came before, these are the achievements of giants standing on the shoulders of pygmies, but they hardly play outside geekdom.
Anyone, therefore, who can awaken a wider sense of the wonder that such knowledge should create is to be applauded. And Dava Sobel, who launched a new genre of popular scientific history ten years ago with Longitude is eminently qualified. The particular part of the universe she has chosen is the solar system — My Very Erotic Mistress Jane Satisfies Unusual Needs Passionately is the mnemonic required to recall the sequence of planets from the sun — combining poetry, history and science to examine what is known about our own stellar backyard.
What emerges most clearly is the sheer chanciness of our particular life-form’s existence. Of our nearest neighbours, Venus’s atmosphere rains vitriolic acid on the ground and bakes it at 400 degrees centigrade, while cosmic rays relentlessly bombard the Martian deserts that lie almost unprotected by its thin atmosphere. Further off, Jupiter’s moons are swept by gales of electrically charged gases, although one, Europa, contains oceans of briny water, and Titan, Saturn’s largest satellite and the last realistic candidate to sustain imaginable life, is sunk deep in clouds of methane. Although some Earthlings just born will surely set foot on another planet, it will take heroic efforts on a positively cre ationist scale for settlers there to avoid evolving into bacteria-like existence as they adapt to their environment.
At her best, Sobel writes beautifully and conveys complex information with elegance and charm, as in this passage on the peculiar pattern of Mercury’s rotation:
The pull of the nearby Sun rushes Mercury around its orbit at an average velocity of 30 miles per second. At that rate, almost double the Earth’s pace, Mercury takes only 88 Earth-days to complete its orbital journey. The same Procrustean gravity that accelerates Mercury’s revolution, however, brakes the planet’s rotation about its own axis. Because the planet forges ahead so much faster than it spins, any given locale waits half a Mercurian year (about six Earth-weeks) after sunrise for the full light of high noon. Dusk finally descends at year’s end. And once the long night commences, another Mercurian year must pass before the Sun rises again. Thus the years hurry by, while the days drag on for ever.
In this vein, The Planets rivals Eugène Marais’ The Soul of the White Ant and Maeterlinck’s The Life of a Bee as a classic of literate science. But as in Maeterlinck, her eloquence has a purple tendency, exaggerated here by an inexplicable decision to describe each planet in a different style thus Mars is the autobiography of a meteorite, Uranus a letter from Caroline Herschel, sister of the planet’s discoverer. As though that whimsy were not enough to clog her fine prose, she throws in chunks of doggerel verse (Robert Frost on Venus, for example: ‘I stopped to compliment you on this star/ You get the beauty of from where you are’) and irrelevant astrological blethers, as though uncertain of her audience’s attention.
One further flaw was unavoidable. Such is the speed of planetary exploration today, the data from the Mars Rovers and the Huygens probe to Titan arrived too late for inclusion, as did the recent electrifying discovery, which might have markedly strengthened the weakest chapter in the book, that the Earth’s molten core revolves faster than its crust.
Despite these failings, Sobel is too imaginative a writer and resourceful a researcher to be set aside. The Planets would be worth reading simply to learn of the startling difference between the inner, solid, sun-derived planets and the outer, gaseous, space-generated hangers-on. It is a bonus to be reminded so vividly of the infinite beauty and frailty of the world and our place in it.
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