Star-crossed lover of our solar-cycle dependency

Today solar astrophysics is big business. One fifth of the world's professional astronomers are engaged in the scientific study of the Sun, as well as the effects of solar activity on the Earth and the space environment. Several space missions support the efforts of ground-based astronomers. For example, the SOHO mission has had our daylight star under continual surveillance for 11 years and has thus observed non-stop through an entire solar cycle.

One of the goals of solar astronomy is to gain a deeper understanding of the complex interaction between the Sun's ever-changing electrical and magnetic fields and the dynamic plasma in its surface layers and atmosphere. Solar flares, powered by the sudden explosion of magnetic energy, add to the drama and the danger: astronauts must be protected from their harmful protons.

Understanding the science of the active Sun began 150 years ago. In The Sun Kings , the accomplished science writer Stuart Clark, who holds a doctorate in astronomy, gives a vivid account of the foundation of solar astrophysics and of the Victorian scientists who unlocked the secrets of the Sun's influence on Earth. This is the most extraordinary book on the history of science I have recently had the pleasure to read. I say that because in producing this compelling page-turner, the author has taken risks with his narrative that will cause professional historians to shudder. No matter. Here is popular science at its best: accurate, meticulously researched, not technical in any way (no equations) and full of adventures.

For a good story we need a tragic character; in this drama, it is accomplished amateur astronomer Richard Carrington, the greatest solar observer in the mid 19th century. Clark shows that by turns Carrington is thwarted in his several attempts to win a post at the Cambridge observatory (where academic skullduggery crushes the outsider); he is ridiculed by the Astronomer Royal; then he falls in love at first sight with Rosa, an illiterate beauty. When he marries her, he fails to notice that her elderly "brother" is in fact her lover. Carrington's dysfunctional triangular marriage can only end disastrously. The moment comes when Rosa's lover draws a knife (Clark is very good at the gory stuff), deeply slashes her arm, twists the knife into her ribs and then throws himself on the weapon.

They both survived, although Rosa was severely traumatised. But the tragedy continued: Rosa died of a medication overdose. At her inquest, Carrington received a stern reprimand for failing to monitor his wife's drugs. The next week he, too, was dead, almost certainly of suicide. And what of the lover? Having survived his attempt at self-harm, he faced 20 years' penal servitude.

On September 2, 1859, solar astrophysics took off. That's because the entire Earth was overwhelmed by the greatest solar outburst in the past 500 years. Auroras erupted from pole to pole, leading to brilliant displays, the light so great that print could be read at night as easily as in daytime. The new fangled electric telegraph system crashed, and magnetic compasses vibrated out of control. Clearly something was afoot in the heavens: Earth was not isolated from the rest of the universe.

Carrington's solar observations of these events ushered in the modern era of astronomy. He had spied a great explosion on the surface of the Sun, a solar flare. His decisive insight was his hunch that the solar outburst and magnetic disturbances were not a coincidence. He suspected what we now term the solar terrestrial connection, namely, that sunspot and flare activity has immediate consequences for our planet.

We currently live in a world where carbon footprints and low-cost airlines are high profile: climate change, and all of that. William Herschel, discoverer of Uranus, addressed the Royal Society with his opinion that sunspot activity would influence the price of wheat. Prolonged periods of few sunspots correlated with high prices for wheat. Lord Brougham dismissed Herschel's speculation as a "grand absurdity", but today we may yet take it to heart.

The many actors in Clark's The Sun Kings rightly include Richard Maunder, who had a rapt fascination with sunspots. It was he who nailed down the 11-year sunspot cycle on an empirical basis, using clues left by Carrington.

Clark's story is that of one of the intrepid astronomers who at the dawn of astrophysics observed the misbehaving Sun and established that its magnetic behaviour had profound consequences for our home planet.

Simon Mitton is a fellow of St Edmund's College, Cambridge.