The Sun Sent a Radio Signal for 19 Days
A solar radio burst lasted nearly four times longer than the previous record and crossed the inner Solar System like a transmission too large for one spacecraft to understand.
What Happened
NASA missions tracked a solar radio burst that persisted for 19 days, demolishing a previous duration record of about five days. The event began in August 2025 and was reconstructed using observations from spacecraft spread across the inner Solar System.
According to [NASA's 2026 account](https://science.nasa.gov/blogs/science-news/2026/05/14/nasa-missions-track-record-breaking-radio-burst-from-sun/), STEREO, Parker Solar Probe, Wind and ESA's Solar Orbiter watched different pieces of the same enormous event as the Sun rotated.
What Made It Strange
Ordinary solar radio bursts rise and fade. This one kept returning. Researchers traced it to a helmet streamer—a vast magnetic structure in the solar atmosphere—repeatedly disturbed by coronal mass ejections. Each disturbance fed energy into the same long-lived radio source.
No single observer had the complete view. The pattern only emerged when measurements from multiple positions were assembled into one moving map. What looked like separate noises became one sustained structure.
The Context
The burst is explained, not extraterrestrial. That does not make it less uncanny. A magnetic formation larger than worlds broadcast across interplanetary space for almost three weeks, while a scattered machine network slowly realised it was hearing the same voice.
Sometimes the signal is simply a star refusing silence.