Some 13,000 years ago, the sun emitted a huge belch of radiation that bombarded Earth and left its imprint in ancient tree rings. That solar storm was the most powerful one ever recorded. The next strongest was the 1839 Carrington Event. It was spurred by a huge solar flare that triggered a powerful geomagnetic storm on Earth.

The resulting “space weather” disrupted telegraph communications around the world. Today, as we move through this year’s “solar maximum,” a period of solar activity that occurs every 11 years, scientists want to prepare governments for the effects of severe solar storms.

In May 2024, Johns Hopkins Applied Physics Laboratory (APL) convened experts for a tabletop exercise designed to test governmental and tribal agency preparations for a strong solar storm like the earlier ones. Solar physicists, space agencies, satellite operators, grid owners, and many others have long known of space weather effects on advanced technologies. The exercise incorporated stakeholders at all levels of government and industry to improve our readiness for space weather events.

Space weather effects

When a geomagnetic storm strikes Earth, a number of things happen. Charged particles from the sun are delivered by the solar wind. That smacks up against our magnetosphere, and those particles get caught up in lines of magnetic force, which results in a lovely display of northern and southern lights. An especially strong storm will cause—among other things—ground currents that can short out electrical power grids and disrupt ground-based communications.

A strong bout of space weather can interfere with (or even destroy) satellites, threaten astronauts in space, disrupt radio communications, and degrade GPS performance. That affects navigation for trains, planes, ships, and cars, and affects cellular networks. Any of those disruptions can interrupt such everyday events as transferring money, making cell calls, and much more. In other words, much of our modern technology is at risk during space weather events.

As an example, in March 1989, a powerful solar outburst triggered a solar storm that resulted in a power outage in eastern Canada. Millions were left without electricity for about nine hours. A power plant in New Jersey was also damaged during the same storm.

In 2024, another storm hit over the U.S. Mother’s Day weekend, resulting in brilliant auroral displays across much of the world. The space weather event also affected some broadcast and radio signals, and some power companies took steps to safeguard their systems. It also affected some satellite communications. That was, by comparison to those in 1989 and 1839, a relatively benign space weather event.

Thanks to lessons learned during prior events, electrical grid and satellite operators (among others) are now better prepared. But more needs to be done to supply early warnings so that governments, companies, and individuals can be ready. That’s where the tabletop exercise at APL comes in handy.

How ready are we for strong space weather?

Space weather understanding and predictions have come a long way since the dawn of the space age and the deployment of sun-watching satellite missions. We do get more early warnings of outbursts, and past events have taught us to “harden” our technologies against geomagnetic storms. However, there are still gaps in agency and government preparedness for and responses to such events.

The tabletop session uncovered many steps necessary to respond when space weather strikes.

“This exercise brought together space weather experts alongside those responsible for emergency management, response, and recovery,” said Ian Cohen, APL Exercise Science Lead. “This helped us scientists to not only provide awareness to these senior leaders, but also highlight the key research and observational gaps, as well as learn how to best communicate the complicated topics of space weather to decision makers.”

In the “After Action Report” from the exercise, released this year, the attendees acknowledged that our preparation is better than in the past, but there are still crucial needs to fill. Among them are better coordination among agencies and other stakeholders to produce meaningful and understandable space weather notifications that outline the impacts on various pieces of infrastructure.

The whole government needs to be involved in such coordination and communication between agencies (such as between NASA and NOAA or NOAA and safety agencies). In addition, upgrades in forecasting and early warning are needed, along with more public education about the effects of space weather and how governments and institutions handle the results of such storms.

In an interesting twist of fate, the tabletop exercise began just as the sun unleashed another burst of radiation and charged particles toward Earth. It resulted in the Mother’s Day storm of 2024 and gave participants in the exercise a chance to go beyond simulated exercises and manage a real-world case of space weather effects on Earth.