Karl Jansky and his Merry-go-Round
Karl Guthe Jansky is known as the father of radio astronomy, because in 1933 he discovered that the center of our Milky Way Galaxy emits radio waves. He was not an astronomer, however. He was a young engineer with Bell Laboratories tasked with identifying sources of static for their overseas radio communications. He built this rotating antenna to get all-sky coverage at their chosen frequency of 20.5 MHz (wavelength about 14.5 meters), and it quickly got the nickname of “Jansky’s Merry-go-round.” With it, he picked up thunderstorms and a strange hiss that moved throughout the day. He eventually figured out that it was coming from the direction of Sagittarius, behind which lies the heart of our Galaxy.