We're getting to that part of the solar cycle during which we should expect to be hit by many solar storms that could endanger our electrical infrastructure.
The biggest solar storm since 2005 is headed our way, according to skywatchers who saw our star let off an M9 flare, just a hair away from the most powerful kind of solar flare. The charged particles hurtling towards Earth are known as a coronal mass ejection, or CME, and we haven't had one this severe since the peak of the last 11-year solar cycle.
The amount of solar activity that can result in big solar storms follows a fairly (but not perfectly) consistent path through time, rising and falling according to mechanisms we don't quite understand. We're just now coming back to the time of peak solar activity, so we could see many more solar storms before we return to the quiet of the trough of the cycle in a few years. If you want to keep track of this stuff, tune in to Spaceweather.com, which obsessively tracks the sun's doings.
To be clear, this storm, while it may cause problems for some satellites and will make for prettier aurorae in the arctic regions near the Earth's magnetic poles, the solar storm only ranks as an S3 on a scale that runs from S1 to S5.
What might happen when we get hit by a much bigger storm? A few years ago, I wrote about a very big storm in 1859 and found that there was so much current in the air that telegraphs could be run without their batteries. It'd be like if the air suddenly started charging your iPhone. Telegraph operators were (rightly) flabbergasted.
"We observed the influence upon the lines at the time of commencing business -- 8 o'clock -- and it continued so strong up to 9 1/2 as to prevent any business from being done, excepting by throwing off the batteries at each end of the line and working by the atmospheric current entirely!" the astonished telegraph operators of Boston wrote in a statement that appeared in The New York Times later that week.
The Boston operator told his Portland, Maine counterpart, "Mine is also disconnected, and we are working with the auroral current. How do you receive my writing?" Portland responded, "Better than with our batteries on," before finally concluding with Yankee pluck, "Very well. Shall I go ahead with business?"
But that was way back at the beginning of the buildout of communications and electrical infrastructure. The damage resulting from a storm like that now would be much, much worse. The National Academies of Science found that if a storm like the 1859 one hit again, it could cause $1 trillion (yes, trillion) in damage.
This month, Gregg Easterbrook dug into some even more exotic possibilities about what the sun could get up to over the coming decades. They range from pretty much nothing to the end of, well, everything.
At least the sun seems unlikely to explode anytime soon. Standard conjecture regarding the inner processes of stars holds that they emit cornucopian amounts of neutrinos, which are subatomic particles. A generation ago, when the first neutrino-detectors were built, they didn't find anything close to the expected number of neutrinos from the sun. This led the late science-fiction writer Arthur C. Clarke, who is credited with the concept of the telecommunications satellite, to speculate that Sol was about to explode, and the human experiment to reach an untimely end.
Today, researchers believe that prior assumptions about solar neutrinos were in error. The sun seems fine. It's not about to explode. Probably. We think.