An eruption on the sun didn't bring the aurora to Pennsylvania or Oregon this week, but more solar outbursts are expected soon

• An eruption on the sun's surface sent plasma and charged particles speeding towards Earth this week.
• Forecasts suggested that this coronal mass ejection would reach our planet Wednesday as a solar storm that could interfere with radio, GPS, and power grids.
• There was a possibility the aurora borealis could be visible from Pennsylvania to Iowa to Oregon, but in the end, the northern lights didn't appear that far south.
• The sun is entering a period of increasing violent activity, so more opportunities for the northern US to see the aurora are likely.

An eruption on the sun this week prompted warnings from the National Weather Service.

The outburst sent plasma and magnetically charged particles, called a coronal mass ejection (CME), speeding towards Earth. If those particles had hit our atmosphere just right, the NWS said, they could have inundated the planet in a geomagnetic storm that would interfere with power grids, GPS, and radio communications, and even affect satellites' orbits around Earth.

These impacts could have extended into the northern US and brought the aurora borealis - a reaction between solar particles and Earth's atmosphere - creeping down into regions from Pennsylvania to Iowa to Oregon.

But when the CME arrived on Wednesday, there were no northern lights in these lower states.

The space-weather branch of the National Weather Service had initially issued a watch for a "strong" geomagnetic storm on Thursday, but it downgraded the watch to "minor" after the CME's arrival.

This was because the CME's magnetic field was pointing north, according to Mike Hapgood, a space-weather consultant at the Rutherford Appleton Laboratory in the UK. It would need to face south in order to wash far enough through the North Pole opening in Earth's magnetic field to reach the US.

"We're unlikely to see much activity, and the aurora will stay further north over Canada," Hapgood told Business Insider. The northern reaches of Maine and Michigan may still catch a glimpse of the green lights, though.

But Illinoisans and Iowans shouldn't despair. There may be better opportunities for them to see the aurora in the near future.

That's because this CME was just a preview of an upcoming period of intense solar activity that could bring more geomagnetic storms and far-reaching aurorae. The sun is entering a new 11-year solar cycle, which means its eruptions and flares will grow more frequent and violent, ramping up to a peak in 2025.

"This is more a wake-up call that stronger storms could occur in the next few years - and we ought to make sure we are ready for them," Hapgood said.

Strong solar storms are fairly common - the NWS estimates that each solar cycle produces about 200 of them - but scientists can't always predict them like this. That often means that power grids and key radio connections are left vulnerable.

NASA is working to better predict space weather

Electric currents from solar storms can travel down Earth's pipelines and power lines, overpowering technologies that humans rely on.

In 1989, an inundation of particles from the sun knocked out Quebec's power for about nine hours. Two other solar storms cut off emergency radio communications for a total of 11 hours shortly after Hurricane Irma in 2017. A solar storm may have even cut off SOS broadcasts from the Titanic as it sank on April 14, 1912.

Bursts of solar activity can also endanger astronauts in Earth's orbit by interfering with their spacecraft or knocking out communications to mission control.

Studying the source of charged solar particles could help scientists figure out how to protect both astronauts and Earth's electric grid from these unpredictable electrical storms. Two spacecraft currently orbiting the sun are doing just that.

In February, NASA and the European Space Agency launched the Solar Orbiter to capture data about eruptions on the sun's surface. NASA's Parker Solar Probe is also zooming around the sun. It's designed to measure solar eruptions as they happen, tracing the flow of material from the sun to the Earth in real-time.

The information these spacecraft are collecting could one day help scientists forecast more geomagnetic storms before they happen.

This story has been updated with new information. It was originally published at 7:34 p.m. ET on December 9, 2020.