Sun unleashes solar storm at Earth, U.S. may see brilliant aurora

The inciting event, which occurred on July 21, is intense but normal. It’s called a coronal mass ejection, or CME. These occur when the sun ejects a mass of super hot gas (plasma). “It’s like scooping up a piece of the sun and ejecting it into space,” Mark Miesch, a scientist with the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center, previously told Mashable. These types of events happen more as the sun approaches the peak of its 11-year solar cycle, which is expected in July 2025.

When these solar particles collide with Earth’s magnetic field, an event called a “geomagnetic storm” can transpire in Earth’s upper atmosphere. Many particles slam into molecules in the air, following magnetic lines to the poles where they deposit energy and produce fantastic atmospheric radiance (popularly called the Northern Lights in the Northern Hemisphere).

“The aurora may become visible over some northern and upper Midwest states from New York to Idaho,” the Space Weather Prediction Center wrote on July 23. “Those wishing to see the aurora should visit our webpage for updates.”

This last sentence is crucial: These are natural, variable events. Nothing is guaranteed, but certain regions may indeed be treated to a light show on July 24. You can check the Space Weather Prediction Center homepage, which includes an aurora forecast.

A graphic from the Space Weather Prediction Center announcing the expected geomagnetic storm on July 24, 2024.
Credit: NOAA / Space Weather Prediction Center

Earlier this year, in May, multiple coronal ejections created vibrant aurora across large swathes of the Northern Hemisphere, in areas that rarely see these atmospheric lights.

While such solar storms can sometimes pose serious threats to our power grids, satellites, and electrical infrastructure, fortunately these formidable events don’t pose a threat to life on Earth’s surface. Earth boasts both a robust magnetic field and atmosphere, which keep dangerous cosmic particles away from our fragile flesh.

“Without those we would be in real trouble,” Bennett Maruca, an assistant professor of physics and astronomy at the University of Delaware who researches the sun, told Mashable.

An image of a CME impacting an illustration of Earth’s magnetic field, shown by the blue lines.
Credit: SOHO / LASCO / EIT (ESA & NASA)

Well above our clouds and weather, both the ionosphere and thermosphere (together ranging from some 50 to 400 miles up) absorb charged particles and damaging radiation, like X-rays and UV rays. Meanwhile, our planet’s magnetic field loops out from the poles into space, trapping a lot of harmful solar energy a safe distance away (and in some cases deflecting these energetic solar particles).

Stay tuned for more space weather this year — some of it may light up our skies.