Coronal mass ejections (CMEs), or bursts of plasma and magnetic field from the sun's corona, have much in common with pandemics. They follow a cycle, albeit a far more regular one (the conditions are ripe every 11 years or so) [source: NASA]. They also cause variable but potentially ruinous damage, and their destructive scales depend, in part, upon humans' connectedness.
In 1859 amateur astronomer Richard Carrington observed a solar flare that heralded a geomagnetic storm. The burst of magnetized plasma that struck Earth built enough electrical ground charge to power telegraph transmissions for days [source: Billings]. Since then, astronomers have watched for such Carrington events (powerful solar storms) and their linked CMEs with mounting concern.
We've been lucky so far. A trick of magnetic field alignment tempered the impact of a sizable CME in October 2003. It nevertheless caused hundreds of millions of dollars in damages by disrupting flights, satellites and power grids. In July 2012 another CME barely missed us [source: Billings].
In the worst case, a CME could cause continental power outages and loss of GPS satellites. That would mean no commerce, no refrigeration and no fuel or water pumps, amounting to trillions of dollars in damages and untold casualties. Some experts cheerfully predict outages would last a few weeks at most. But a quick about-face would prove impossible if, as some people fear, the CME's ground current cooks all the transformers. In that case, the risks of social breakdown and mass starvation become quite real [source: Billings].