NASA on Brilliant Auroras: 'We'll Be Studying This Event for Years'

While the powerful solar storm that hit our planet last weekend triggered spectacular aurora displays across large swaths of the world, it was also a golden opportunity for NASA to study space weather.

The May 10 "extreme" G5 geomagnetic storm, sparked by a series of coronal mass ejections from the sun, was the most powerful in decades, and led to auroras being seen across all 50 U.S. states and beyond.

This storm, as well as an X8.7-class solar flare on May 14 that was the most powerful this solar cycle, has been a bounty for NASA space scientists to study how the sun can impact Earth.

"We'll be studying this event for years," Teresa Nieves-Chinchilla, acting director of NASA's Moon to Mars (M2M) Space Weather Analysis Office, said in a NASA statement. "It will help us test the limits of our models and understanding of solar storms."

The May 10 geomagnetic storm was the first G5 storm we have seen since 2003. Geomagnetic storms—which are disruptions in the Earth's magnetic field—are scaled between G1 (minor) to G5 (extreme), with their strength depending on the speed and magnetic field of the coronal mass ejection (CME) that collides with the magnetosphere. CMEs are clouds of solar plasma that are thrown out from sunspots and other active areas of the sun, and travel at speeds of around 3 million mph through space. If they hit the Earth, they can cause geomagnetic storms, and result in auroras being seen further away from the poles than usual.

"Storms of this magnitude are rare. On average, they occur around 4 times per 11 years. 11 years is the natural cycle of the Sun's activity, and the G5 events tend to occur close to the peak of that activity cycle. We are currently hitting a period of maximum activity of the current cycle, so these large events are more likely to occur," Huw Morgan, head of the Solar Physics group at Aberystwyth University in the U.K., told Newsweek.

The series of CMEs that triggered the May 10 storm were released from a huge sunspot named AR 13663 that is around 15 times as wide as the Earth. This same sunspot also spat out a number of powerful solar flares—which are bursts of X-ray and ultraviolet radiation—including the X8.7-class flare that led to radio blackouts across the U.S.

"The CMEs all arrived largely at once, and the conditions were just right to create a really historic storm," Elizabeth MacDonald, a NASA heliophysics citizen science lead and a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in the statement.

The auroras caused by the May 10 storm were seen as far south as Florida and Mexico, as well as Germany and Italy, and even northern India. Millions of people around the world snapped the cosmic phenomenon on their phones, with thousands uploading pictures to the NASA-funded Aurorasaurus citizen science site.

"Cameras — even standard cell phone cameras — are much more sensitive to the colors of the aurora than they were in the past," MacDonald said. "By collecting photos from around the world, we have a huge opportunity to learn more about auroras through citizen science."

By studying the auroras, scientists can compare the storms seen today with those from centuries ago, and get an idea of the intensity of storms long gone by. As these aurorae were seen as far south as 26 degrees magnetic latitude, the May 10 storms may have been some of the most powerful in the past 500 years.

"It's a little hard to gauge storms over time because our technology is always changing," Delores Knipp, a research professor in the Smead Aerospace Engineering Science Department and a senior research associate at the NCAR High Altitude Observatory, in Boulder, Colorado, said in the statement. "Aurora visibility is not the perfect measure, but it allows us to compare over centuries."

NASA researchers hope to learn as much as possible about how space weather and solar ejections affect satellites and spacecraft, as this could be a major issue for the upcoming Artemis mission to the moon, and subsequent expeditions to Mars.

The enormous sunspot has now turned away from Earth, but is pointed directly at Mars, and has flung a CME towards the Red Planet.

"The active region is just starting to come into view of Mars," Jamie Favors, director for the NASA Space Weather Program at NASA Headquarters in Washington, said in the statement. "We're already starting to capture some data at Mars, so this story only continues."

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