Karl Guthe Jansky (1905-1950), US radio engineer, with his famous 14.6-metre rotatable, directional antenna system. After studying physics at Wisconsin, Jansky took a job at Bell Telephone Laboratories in 1928. He was given the task of investigating static that interfered with shortwave radio communication. This static was unrelated to common sources, and Jansky demonstrated that it was coming from the centre of our galaxy, in the constellation of Sagittarius. The discovery represented the birth of radio astronomy, where radio waves, generated by stars and planets and containing detailed information, are detected using radio telescopes.