Dutch Astronomer Jan Oort was a Dutch astronomer who made significant contributions to the field of astronomy. He is best known for his hypothesis that the Milky Way is surrounded by a large cloud of comets, now known as the Oort Cloud. He also made important contributions to the study of stellar motions and the structure of the Milky Way. He was awarded the Bruce Medal in 1950 and the Gold Medal of the Royal Astronomical Society in 1960.