On August 21, 2025, the Sun emitted what appeared to be a routine burst of radio-wave energy—the kind astronomers observe regularly and expect to fade within hours or days. But this signal refused to disappear. As scientists continued to track it, the burst stretched on far beyond anything previously recorded, ultimately becoming the longest-lasting solar radio burst ever observed. A team of researchers analyzed the event using data from four different NASA missions, which all happened to observe the radio burst for a few days over three successive windows. The record-breaking radio burst lasted for a total of 19 days, beating the previous record of just five days. The team’s findings, published in The Astrophysical Journal Letters, helped pinpoint the exact source of the radio burst and could aid scientists in better forecasting space weather. Solar outburst The Sun is colossal sphere of superheated plasma that’s constantly plagued by violent eruptions. Solar flares, or massive bursts of energy that erupt from the surface, accelerate tiny particles like electrons in the Sun’s atmosphere. As those electrons move through the Sun’s plasma, they send out intense radiation in the form of radio waves.