A "very rare" geomagnetic storm reached Earth hours earlier than expected on Friday, prompting the National Oceanic and Atmospheric Administration to issue its first rare geomagnetic storm warning in nearly two decades.
Operators of power plants and spacecraft in orbit were recommended to take precautions ahead of time as the G4 geomagnetic storm posed a risk for high-voltage transmission lines and satellites, which could in turn disrupt navigation and communication. The Federal Emergency Management Agency was also notified.
But across the world, people sat back and watched as darkness set in and stunning light displays surfaced.
Others stood by and waited patiently - knowing they couldn't do anything else.
“For most people here on planet Earth, they won’t have to do anything,” said Rob Steenburgh, a scientist with NOAA’s Space Weather Prediction Center.
Geomagnetic storm conditions were expected to continue through the weekend as additional coronal mass ejections headed toward earth.
CME’s are "large expulsions of plasma and magnetized particles from the Sun’s corona," according to NOAA's Space Weather Prediction Center. Those ejections can expand in size as they approach Earth, and can cause geomagnetic storms when they arrive.
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Conditions will peak at around 1 a.m., when the solar storm reaches 8 on the KP index, a nine point scale that measures aurora strength.
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The storm could produce northern lights in a number of states, including Illinois, and stretch as far south as Alabama. But where you'll be able to see them in the Chicago area remains up in the air.
Scattered showers and storms could hinder the visiblity, according to the NBC 5 Storm Team.
If we're lucky and the skies are clear, don't expect dramatic curtains of color normally associated with the northern lights. Instead, we'll see more like splashes of greenish hues, according to experts.
The northern lights, or aurora borealis, typically come from charged particles that spew from the sun during solar storms. The colorful displays are created when clouds of these energetic particles slam into Earth’s magnetic field and interact with the atoms and molecules in the planet’s upper atmosphere.
The northern lights typically light up the night sky at high latitudes, but during intense periods of solar activity, they can be spotted farther south than usual.
While this geomagnetic storm is said to be "very rare," how often does one of this scale occur?
Only three other "severe" geomagnetic storms, classified as G4s, have been reported in the past five years. The last "extreme" event, a G5 storm, occurred around Halloween in 2003, resulting in power outages in Sweden and damaged transformers in South Africa.
The most intense solar storm in recorded history, in 1859, prompted auroras in central America and possibly even Hawaii. “We are not anticipating that” but it could come close, said NOAA space weather forecaster Shawn Dahl.
Even when the storm is over, signals between GPS satellites and ground receivers could be scrambled or lost, according to NOAA. But there are so many navigation satellites that any outages should not last long, Steenburgh noted.
