1843-1928

U.S. geologist recognized for advancing geological education and shaping the planetesimal hypothesis. This hypothesis states that a star passing near the sun broke into pieces that condensed and clumped together to become planets. Chamberlin became chief of the Wisconsin Geological Survey in 1881 and later became the president of the University of Wisconsin at Madison. Then, for 26 years, he was head of the University of Chicago geology department, developing it into a world leader in the field of geology. However, his most famous contribution came after retirement with the development of the planetesimal hypothesis.