The Sun is a relatively quiet G-type star (G2V), but the key word is “relatively.” While it avoids the massive storms known to affect so-called flare stars, it occasionally releases both solar flares and coronal mass ejections. On March 20, NASA detected such a flare with an associated CME. The coronal mass ejection will hit Earth on March 23 and may push the northern lights far south, lighting up skies in the northern United States and southern Canada.
Flares and CMEs are related but distinct events. Both occur near sunspot groups and are related to sudden shifts in the Sun’s magnetic field. A solar flare releases large amounts of radiation, in addition to some high-energy particles, but the energy released is dissipated in every direction rather than being aimed at a particular location. A coronal mass ejection, as the name implies, involves actual stellar material being shot into space. This disturbance can drive a shock wave in front of it, increasing the total impact on any planet that it hits. As NASA describes:
The flare is like the muzzle flash, which can be seen anywhere in the vicinity. The CME is like the cannonball, propelled forward in a single, preferential direction, this mass ejected from the barrel only affecting a targeted area. This is the CME—an immense cloud of magnetized particles hurled into space. Traveling over a million miles per hour, the hot material called plasma takes up to three days to reach Earth. The differences between the two types of explosions can be seen through solar telescopes, with flares appearing as a bright light and CMEs appearing as enormous fans of gas swelling into space.
We’ve talked about CME’s before, and the potential damage that they could pose to modern life on Earth. The good news is, the incoming CME headed for Earth today is a G2 storm. Roughly 600 of these occur every 11 years, though most of them don’t hit the Earth. A truly powerful storm, like the 1859 Carrington Event, would be classified as a G5.
The good news is if you’re in-between the green and yellow lines, you’ve got a solid shot of being able to see the event and its impact on the Aurora Borealis, or northern lights. NASA expects the aurora to be visible between the two lines early in the AM. If you’ve got a chance, try to sneak out and check out the light show if you’ve never seen it.
At these intensities, a CME is an interesting opportunity to see the way charged particles interact with the magnetic field. At higher intensities and in rarer events, the outcomes can be far more serious. We’ve explored those issues and the tremendous damage a Carrington Event could do to the modern-day electrical grid in multiple stories over the years. A former colleague of mine from some years ago has also recently written a guide on the potential dangers of EMP explosions from both solar and nuclear sources that discusses this issue extensively as well.
Once you start learning about them, CMEs are a hard class of natural disaster to completely dismiss. On the one hand, the odds of being struck by a G5 solar flare are low. On the other, we know for a fact that the Earth occasionally gets nailed by a nuclear fastball flung by a nearby stellar object we literally worshipped as a deity for thousands of years. It’s as close as one can reasonably get to being smited, smitten, smote, struck by the hand of an angry god.
The impact on the world’s electrical grid, particularly the North American grid, could be substantial depending on where and when the flare hit. Much of our own electrical generating capacity could be offline for months to years depending on just how bad the disaster is. The modern grid isn’t remotely designed to cope with the impact of a G5, the damage to power plants from smaller storms has been significant, and the utility companies generally refuse to acknowledge that they’ve overlooked a potentially massive source of damage that we know occurs every few hundred years based on previous records of CME events on Earth.
Immediate threat? No. Interesting rabbit hole? Definitely. Something we really ought to be prepping for more seriously than we have? Goes without saying.
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- The solar storm of 2012 that almost sent us back to a post-apocalyptic Stone Age