While our attention has been focused on hurricanes and wildfires, our planet was busy dodging a cosmic bullet—one that Dr. Don Lincoln, a senior physicist at Fermilab, says, “could have crippled human technological civilization.”
In the past week, the sun has experienced a series of unusually energetic solar flares. A solar flare is the result of the magnetic energy in the vicinity of a sunspot being released. The result is a bright spot on the sun that takes place over a period of about 10 minutes.
According to an article published by Dr. Lincoln on CNN:
The flare can shoot out a broad range of electromagnetic energy, from visible light to X-rays to the even more energetic gamma rays. If this emitted energy is aimed at the Earth, it can have a significant impact, including enhanced auroras at lower latitudes, and airline passengers can experience a higher radiation dose than usual, especially for flight paths near the Earth’s poles. This radiation dose is not deadly, although, during especially bright solar flares, the airlines alter flight paths to avoid getting closer than 780 nautical miles to the poles.
Solar flares are rated on an increasing scale: A, B, C, M, X, with each category being 10 times more powerful than the previous one. Every flare has an accompanying number that gives more information; for instance, an X3 flare has triple the energy of an X1, and so on.
Several X and M class flares have occurred over the last week, with an X9.3 flare occurring on September 6. A second severe flare of class X8.2 was seen on September 10. In comparison, the strongest flare to have its strength measured was a category X28 which occurred back in 2003.
The energy emitted from these flares is significant, but fortunately, the Earth’s atmosphere protects people on its surface for adverse effects. The flares did temporarily block high-frequency radio communication.
Satellite interference is the least of our worries, however. A more dangerous side effect is a coronal mass ejection (CME), which often accompanies a flare. A CME occurs when some of the sun’s ionized material is injected into space. Though last week’s flares did have a CME, it didn’t hit Earth as harshly as it could.
If the CME had been aimed at Earth, the ionized particles could have slammed into the magnetic field and distorted its shape in a massive geomagnetic storm. The impact could have induced electrical currents on the Earth’s surface—and the danger of this effect is hard to overstate.
It was a close miss, but incidents like this highlight the vulnerability of our systems.