Sunstorm by Arthur C. Clarke Page B

with much more vigor than at its minimum. Mikhail sketched the accepted mechanism behind the solar cycle. A “meridional flow” of plasma over the sun’s surface from equator to poles carries the relics of sunspots north and south. At the poles the cooling material sinks down into the body of the sun as far as the base of the convective zone, and then migrates back toward the equator. But the magnetic scars left by sunspots linger on through this cycle, ghosts that seed the next generation of active regions.
    Mikhail described the complicated relationship of sun, Earth, and humanity.
    Even in historical times the sun’s variability has affected the Earth’s climate. For more than seventy years, from around 1640 to 1710, very few sunspots were observed on the sun’s face—and the Earth was plunged into what the climatologists call the “Little Ice Age.” Europe suffered severe winters and cool summers; at the peak of it, in 1690, London children ice-skated on the Thames.
    In the electronic age, a growing dependence on high technology made humans much more vulnerable to even mild solar tantrums. In April 1984 a flare knocked out communications on
Air Force One;
President Reagan, over the mid-Pacific, was left incommunicado for two hours. Before June 9 the most intense storm on record had occurred in September 1859; that one had melted telegraph wires.
    “We actually came close to that again in 2003,” Mikhail said. “The sun suffered two eruptions in successive days, aimed right at the Earth. We were saved from more severe effects only by a chance alignment of magnetic fields.”
    Rose Delea was getting restless. “All these phenomena are well known.”
    Mikhail said, “Yes, we think we are getting a handle on measuring the effects of these different solar glitches—and predicting them, though that’s still more an art than a science . . .” He put up a slide of three “space weather scales” that the current Space Weather Service had inherited from the old American Space Environment Center, and had elaborated on since. “You can see we describe three types of problem for Earth: geomagnetic storms, solar radiation storms, and radio blackouts. Each type is calibrated with these scales, from one to five—one being minor, and five being severe.”
    Siobhan nodded. “And June 9—”
    “June 9 was principally an outcome of a coronal mass ejection, and would be measured by our G-scale, our geomagnetic-storm scale.”
    “And its rating?”
    “Off the scale. June 9 was unprecedented. But the irony is that the event was better predicted than any solar glitch in history, thanks to Doctor Mangles.” He glanced at Eugene.
    But Eugene, as distracted as ever, didn’t react to the cue; he seemed barely aware that the rest of the group existed.
    There was an awkward silence. Bud called for a break.
             
    You had to fetch your own coffee, it turned out; there were no spare hands to fetch and carry. And there were no digestive biscuits, not one on the whole damn Moon.
    A line quickly formed at the coffee spigot at the back of the room. But Mikhail, near the front of the queue, picked up two plastic beakers of coffee and tentatively approached Siobhan, who accepted a beaker gratefully. Mikhail’s face was lugubrious and crumpled, and his voice was warm and rich; Siobhan liked him instinctively.
    He said, “I imagine you’re the first Astronomer Royal to visit the Moon?”
    “You know, I don’t think any of us even left Earth before.”
    “Flamsteed would be proud of you.”
    “I like to think so.” She sipped her coffee, and couldn’t help but grimace.
    He smiled. “I apologize for Clavius coffee. And for the reception you’ve received here. We Moon-folk are an odd lot. A small society.”
    “I was expecting a certain insularity.”
    “But it’s more than that,” Mikhail said. “We are very self-reliant—we have to be. But that breeds a certain indifference to outsiders, and sometimes