The American radio engineer, Karl Jansky, 1905- 1950. After studying physics at Wisconsin, Jansky took a job at Bell Telephone Co in 1928. He was given the task of investigating static that inter- fered with shortwave radio communication. This static was unrelated to common sources, and Jansky demonstrated that it was coming from the centre of our galaxy (constellation of Sagittarius). In 1932 he suggested it was caused by interstellar ionized gas. This received little attention. But this discovery represented the birth of radio astronomy, in which microwaves are received from space and interpreted. The unit of radio emission strength, the jansky, was named in his honour.