(1868-1938), American astronomer

George Ellery Hale, born on 29 June 1868 in Chicago Illinois, was an American astronomer who helped created the discipline of astrophysics. Hale was born into a wealthy Chicago family and from an early age was enraptured by science. He built his first observatory at age 20 at the Hale home and acquired a professional long-focus refractor and spectroscopic apparatus. Graduating from the Massachusetts Institute of Technology with a bachelor’s degree in physics in 1890, Hale explained in his senior thesis his design for a spectroheliograph.

Hale’s work and his observatory came to the attention of William Rainey Harper, the first president of the new University of Chicago. In October of that year, Harper and Hale secured support to build the Yerkes Observatory with a 40-inch (102-cm) refractor, the largest in the world. In 1894 Hale founded The Astrophysical Journal, which helped professionalise astrophysics.

In 1904 Hale established an observing station, the Mount Wilson Solar Observatory, at the summit of Wilson’s Peak in southern California. A 60-inch reflector was installed at Mount Wilson four years later at an independent facility. Hale was a major driver in the establishment of the American Astronomical Society in 1899 and in 1904 he founded the International Union for Cooperation in Solar Research (transformed into the International Astronomical Union after World War I). Fascinated with the structure of sunspots, Hale was able to show by 1908 that they were magnetically active storms of swirling gas in the solar photosphere.

Well before his 60-inch reflector was in operation on Mount Wilson, Hale had set his sights on a 100-inch (254-cm) reflector. The 100-inch reflector finally became operational at Mount Wilson in 1918. Hale had for a third time built the largest telescope in the world. In the interim, he focused on his creation in July 1916 of the National Research Council (NRC), which marshalled scientific expertise for national needs, specifically to ready the country for war. Hale spent most of the war years chairing the NRC in Washington, D.C., and as a result became a central figure in the postwar reorganisation of international science.

In 1928 he attracted some $6 million from the Rockefeller Foundation’s International Education Board for the construction of a 200-inch reflector. Over the next two decades there would be many technical and social obstacles to the completion of the telescope. Hale died on 21st February 1938 in California, and construction of the telescope was halted during World War II (1939–45), but eventually, in 1949, the 200-inch Hale Telescope at the Palomar Observatory saw first light. It was the largest telescope in the world until 1976.