Why a severe solar storm could be catastrophic for Earth
19 May 2025

Last year, the US government performed an exercise to test its preparedness for a catastrophic solar storm.

The exercise was conducted by the Space Weather Operations, Research, and Mitigation (SWORM) task force, which includes the National Oceanic and Atmospheric Administration (NOAA) and the Department of Homeland Security (DHS).

A report on the findings has now been released, highlighting challenges in predicting space weather.

It also mentioned that an extreme event could damage US's critical infrastructure and threaten its national security.

Drill highlights vulnerabilities in space weather forecasting
Exercise details

The unique drill was conducted in May 2024 at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland and a Federal Emergency Management Agency (FEMA) site in Denver, Colorado.

The exercise was split into four modules simulating different solar events and their harmful impacts on terrestrial and extraterrestrial systems.

These included radio communication blackouts, GPS failures, power outages, increased radiation exposure for astronauts/satellites, and loss of tracking/communication with orbiting satellites.

Future solar storm scenario imagined
Simulation

One module asked participants to imagine a hypothetical solar storm scenario over eight days in January and February 2028.

In this simulation, NOAA detected an active region on the solar surface that was aligned with Earth.

The exercise involved two astronauts heading to the Moon aboard Orion spacecraft while another crew was already on the lunar surface as part of Artemis missions.

Participants had to consider their agency's preparedness for such an event.

Geomagnetic storm coincided with US solar storm drill
Storm impact

Interestingly, the largest geomagnetic storm in over two decades coincided with the exercise.

On May 10, 2024, a G5 geomagnetic storm struck Earth due to large plasma expulsions from the Sun's corona (coronal mass ejections).

The G5 storm significantly disrupted Earth's power grid and created stunning auroras globally.

It also increased atmospheric density in low Earth orbit by up to an order of magnitude, causing atmospheric drag impacting satellites.

Difficulty in predicting solar storm impact
Challenges

Space weather forecasters keep track of the Sun's activity and incoming CMEs, but predicting these storms is still difficult.

Shawn Dahl, service coordinator for the Space Weather Prediction Center, explained, "We never know what's actually going to be, what the CME is composed of, and what to make of it until it gets just 1 million miles from Earth."

He added that they can only determine the composition of CME when it's about 15-45 minutes away from our planet.

Investment in space weather monitoring required
Recommendations

Among other things, the report recommended investing in next-generation space weather satellites and developing more sensors to monitor drivers of space weather. It also suggested that US agencies collaborate with international partners and the private sector.