British physicist James Stanley Hey discovered that the Sun emits radio waves, on February 27, 1942. His accidental discovery gave birth to solar radio astronomy and was crucial for both military radar development and the expansion of astronomy beyond the visible spectrum.
Hay had been tasked with solving WWII radar jamming; determined that the intense, noise-like interference was originating from a large sunspot and not from enemy jamming. Proving the Sun was a source of, not just visible light, but radio emission from an active sunspot. The finding was kept quiet for military reasons, Hey went back to study the radio waves after the war and confirmed in 1946 that these intense radio bursts from the Sun coincided with solar flares. More
