NASA's PUNCH Nails Solar Storm Arrival to Within 30 Minutes in Proof-of-Concept Test

NASA's PUNCH mission predicted the near-Earth arrival of a solar eruption to within 30 minutes in an initial proof-of-concept test, using continuous imagery to track the storm across the inner solar system. The result, roughly 10 times more precise than current methods, could reshape how Earth-impacting storms are forecast. The findings were presented Tuesday at the Committee on Space Research Scientific Meeting and are under review at the journal Space Weather.

Solar storms are caused by coronal mass ejections, huge explosions of material off the Sun. Forecasting when these ejections reach Earth is central to mitigating their impacts on power grids, satellites, and astronauts. Until recently, coronal mass ejections could not be tracked continuously for much of their journey, and could only be observed as they traversed about one-fifth of the distance from the Sun to Earth, leaving scientists to guess the rest.

The PUNCH mission, launched in 2025, changed that. Its four spacecraft in low Earth orbit make continuous 3D observations of the inner solar system, capturing a new image every four minutes with a wide field of view that lets scientists track coronal mass ejections nearly all the way to Earth.

Scientists tested the approach using data from a coronal mass ejection that left the Sun on May 31, 2025. They fed PUNCH images into a computer model that analyzed the leading edge of the ejection over time, using its speed and geometry to calculate an arrival time. Twelve hours after the ejection left the Sun, the model settled on a final prediction showing the storm would arrive eight hours later. That prediction proved accurate to within a half hour, making it 10 times better than current methods, which provide only a five-hour window. The model also revealed when its estimate had stabilized, giving forecasters a way to predict arrival with confidence.

"We thought PUNCH would be good at this, but it's a stunning result," said Craig DeForest, principal investigator for PUNCH at Southwest Research Institute's Solar System Science and Exploration Division in Boulder, Colorado. "To put it in perspective, this could be the space weather equivalent of going from a steam engine to a modern internal combustion engine." He added that the team achieved "an order of magnitude better result than the state-of-the-art method with a really basic process, just informed by the fact that the coronal mass ejection could be tracked continuously across the solar system."

The results demonstrate the power of PUNCH's wide-field imagery to track solar events as they move out from the Sun. Beyond forecasting, the high-resolution images allowed scientists to see new structures in coronal mass ejections, revealing that the clouds of material are clumpier than previously thought and continue to evolve as they cross the solar system. The data is also helping scientists better understand how plasma moves across space, insight that can extend to how plasma behaves elsewhere in the galaxy, including in star-forming regions.

The scientists believe that with more refined PUNCH data and better models, they could forecast coronal mass ejection arrival times even further in advance. Southwest Research Institute, based in San Antonio, leads the mission and operates the four spacecraft from Boulder. The mission is managed by Space Science Mission Operations at NASA's Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at agency headquarters in Washington.