The 1942 Discovery of Solar Radio Bursts During World War II Signals Birth of New Astronomical Field

Discover how WWII radar interference led James Stanley Hey to identify solar radio bursts, founding the field of solar radio astronomy in February 1942.

By: AXL Media

Published: Feb 28, 2026, 4:35 AM EST

Source: The information in this article was sourced from Astronomy

A Mysterious Case of Wartime Radar Interference

During the height of World War II, the British military faced a sudden and alarming technical crisis when anti-aircraft radar stations along the English coast were struck by severe electronic interference. On February 27, 1942, operators reported a massive wall of noise that threatened to render their defensive systems useless. Given the geopolitical climate, the immediate assumption was that German forces had developed a sophisticated new method of signal jamming. The disruption was treated as a high-level security threat, sparking an urgent investigation into the origin of the anomalous signals that were blinding the nation's primary warning systems.

Deducing the Solar Origin of Electronic Noise

Physicist James Stanley Hey, working with the Army Operational Research Group, was tasked with analyzing the data from the affected radar sites. Hey noticed a peculiar pattern that did not align with typical enemy tactics: the interference began precisely at sunrise and ceased at sunset. Recognizing that the timing suggested a celestial rather than a military source, Hey consulted with the Royal Greenwich Observatory. He discovered that a massive sunspot group was currently traversing the solar disk. By correlating the radar noise with the position of these solar features, Hey realized that the Sun itself was emitting powerful radio bursts.

The Transition from Secrecy to Scientific Milestone

Because the discovery involved sensitive radar technology and defense research, Hey’s findings were classified as a state secret and could not be shared with the broader scientific community immediately. It was not until the conclusion of the war that the data was finally declassified and published. This delay meant that while the discovery was made in 1942, the world did not fully recognize February 27 as a pivotal date in science until years later. The eventual release of this information transformed the Sun from a purely optical subject of study into a dynamic source of radio-frequency radiation, fundamentally altering our understanding of solar-terrestrial physics.