Karl Jansky: The Engineer Who Opened a New Window to the Universe

On October twenty-second, nineteen hundred and five, Karl Guthe Jansky was born in Norman, Oklahoma, USA. He was a physicist and radio engineer, and his work on radio wave noise paved the way for an entirely new scientific discipline: radio astronomy.

While working for Bell Telephone Laboratories in the early nineteen-thirties, Jansky was tasked with investigating sources of static that could interfere with transatlantic radio communication. He built a peculiar, rotatable antenna system and identified three main sources of noise: nearby thunderstorms, distant thunderstorms, and a faint, persistent hiss of unknown origin. Through careful observation over a long period, he discovered that this third type of noise came from the center of the Milky Way in the constellation Sagittarius. In nineteen thirty-two, he announced his discovery: he had received radio waves from space. This discovery, which showed that celestial bodies emitted energy at radio wavelengths, was the birth of radio astronomy. Although Bell Labs did not pursue his finding further, Jansky had opened an entirely new spectrum for astronomical observation, which has since led to the discovery of pulsars, quasars, and the cosmic microwave background radiation.