Could a space storm heading toward Earth from the sun disrupt power grids, satellites and some high-frequency communications? Experts say it could.
The problem is something called a coronal mass ejection, a massive solar event in which a huge bubble of plasma lifts off the sun's surface at incredible speeds. The result is a burst of charged particles and gas racing through space.
How does a CME affect Earthly gadgets? The answer has to do with the magnetic field which encircles Earth as lines of force arching between the north and south poles.
Attack of Charged Particles
The sun gives off a steady stream of charged particles known as the solar wind. When those charged particles, negatively charged electrons and positively charged protons, enter the atmosphere, rather than continuing on their journey Earthward, they are deflected along the lines of force of the Earth's magnetic field.
As the particles move north and south, they spiral towards Earth, striking atoms and ions in the atmosphere. These in turn emit electromagnetic radiation in the form of visible light, which we see as a sheet of shimmering light known as an aurora.
Aurorae are most common within two rings around the Earth, one lying between 10 degrees and 20 degrees distance from the north magnetic pole (aurora borealis) and the other lying between 10 and 20 degrees distance from the south magnetic pole (aurora australis).
Generally speaking, the solar wind is relatively constant. As a result, the Earth's magnetic field is fairly constant as well. But when an event like a CME takes place, the atmosphere is flooded with an unusually high concentration of charged particles. That causes the strength of the magnetic field to fluctuate. This is known as a geomagnetic storm.
According to the laws of electricity and magnetism, when the intensity of a magnetic field fluctuates, it can generate a current in conductors that are within the field.
The long cables that made up a telegraph system, or that are part of our existing telephone systems and power grids, are conductors that are highly susceptible to such fields.
During one intense geomagnetic storm in 1859, for instance, telegraph operators in New England disconnected the battery that powered telegraph transmission between Boston and Portland, Maine, and operated strictly using the electricity generated by that evening's aurora for nearly two hours.
Such currents can be problematic for sensitive electric grids because they can cause the voltage to vary between grounding points on a system, leading to power surges that can wreak havoc, overloading transformers and overwhelming voltage regulators. This is what happened to Hydro-Québec during a widespread blackout in 1989 that left 6 million Canadians in the dark.
Researchers believe portions of the North American power grid that happen to be situated in more northerly latitudes (which is closer to the ring where aurorae are most likely to occur) and atop geological formations that consist largely of igneous rock (which has high electrical resistivity) are especially vulnerable.
That would include most of eastern Canada, a good deal of New England, and a big swatch of the Pacific Northwest.
Still, history shows there is only a very slim chance that a solar storm could lead to a blackout anywhere.
And while the prospect of disrupted technology may be worrisome, there is a flip side. Intense solar activity and solar mass ejections can create brilliant, shimmering aurorae, which are an unforgettable sight for those lucky enough to be looking up at a dark sky at the right place and time. NASA scientists predict the northern lights could be visible as far south as Oregon and Illinois.