When the sun got ornery in 1859, telegraph operators saw sparks fly. A huge solar flare belched a cloud of charged particles into Earth's path. But other than frying telegraph lines, the electromagnetic collision caused little stir. Nobody back then had yet switched on a decent light bulb, much less charged an iPhone.

Yet the sun hasn't changed its ways, and that worries University of Kansas physicist Adrian Melott, among others. If the remnants of a similar solar flare struck the planet today? "Gee, I'd be without cable TV," Melott deadpanned.

Without e-mail too, some fear. No heating or cooling. No electric grid. Satellite technology, it was nice knowing you.

This is the scenario rolling out from a growing network of scientists, policymakers and survivalists. Not quite doomsday because life itself would continue, but a silent natural disaster that could unplug us from all we depend upon. "It's happened before, as recently as 1989," said astrophysicist David Hathaway of

NASA's Marshall Space Flight Center in Huntsville, Ala.

Scientists regard what happened then as a sun-to-Earth wake-up call, an electromagnetic puff, though strong enough to knock out power in Quebec and parts of the U.S. Northeast. Hathaway said the Big One "could be catastrophic," leaving much of North America without juice for months or years. A 2009 study by the National Academy of Sciences warned that a massive geomagnetic assault on satellites and interconnected power grids could result in a blackout from which the nation may need four to 10 years to recover.

"The Earth is in peril, and people love that," said Benjamin Radford, deputy editor of Skeptical Inquirer magazine. "There is this certain human fascination with disaster. … But given a world so interconnected and dependent on technology, with all our cellphones and computers, there's some legitimate scientific concern about this."

Because solar storms occur regularly, with magnetic loops flaring and twisting around sunspots, government weather scientists say it's inevitable that Earth will, on rare occasion, get bonked by what they call a "coronal mass ejection." A cloud of solar plasma could penetrate and shake the planet's magnetic field, if the sun's aim is just so.

Some say a super coronal mass ejection, capable of shorting out satellites around the globe and frying electric lines across a continent, might be a once-in-a-century event. The uncertainty rests in the brief span of time in which scientists have recorded a link between sunbursts and electromagnetic fluctuations on Earth, the first being astronomer Richard Carrington's observations in 1859. And even then, the world knew about it only because technology went haywire.

Sparks shocked telegraph operators and set fire to their paper. Newspaper accounts said the Northern Lights could be viewed as far south as the Caribbean, the result of electrically charged particles from the sun entering Earth's atmosphere.

In Washington, concerns about an epic sunstorm have forged unusual alliances. Policymakers on the right have joined liberals such as Rep. Henry Waxman, D-Calif., to push legislation requiring utilities to toughen the electric infrastructure. But such a bill never gained traction in the Senate.

Experts say solutions range from upgrades that keep power surges from spreading, to sheds that protect big transformers, to rockets at the ready to carry communications satellites into space, replacing a bunch of dead ones. "If a once-in-a-millennium event does come along, what can you do now that you know is going to work?" asked Allen Klassen, of power company Westar.