When George Ellery Hale started at MIT in 1886, he found his textbooks distracting; he barely passed organic chemistry on the way to his bachelor’s degree in physics four years later. Yet he was to become one of the luminaries of solar astronomy, and one of his most important achievements was an invention he created during those undergraduate years.
Something of a loner, Hale was always happiest peering through a telescope. He spent his free time researching astronomy at the Boston Public Library (MIT was then in the nearby Back Bay neighborhood) and volunteering at the Harvard College Observatory under Edward C. Pickering, who had previously taught at MIT. During school breaks, Hale would retreat to his parents’ home in Chicago, where he had set up a solar observatory in the attic. His dedication paid off in his last year at MIT, when he constructed the first successful spectroheliograph–an instrument that recorded, on a photographic plate, wavelengths emitted by individual elements present in the sun. The instrument enabled him to produce detailed images of sunspots as well as the loops of relatively cool plasma known as solar prominences. His 1890 senior thesis, “Photography of the Solar Prominences,” reported his revolutionary results. “Nearly all our existing knowledge regarding the … forms and motions of prominences, details in the [sun’s atmosphere], and the structure of the solar surface around sunspots is due to the spectroheliograph or to some adaptation of its principles,” a prominent astronomer would write upon Hale’s death in 1938.
Hale thought about the sun constantly, even while on his honeymoon with Evelina Conklin, whom he married two days after his graduation. The young couple made a stop at Lick Observatory, near San Jose, CA, where a fellow astronomer entertained Evelina while Hale stargazed. Back in Chicago, with his father’s support, Hale expanded his home laboratory into the Kenwood Astrophysical Observatory. In 1892, at age 24, he began teaching astrophysics at the University of Chicago and donated the Kenwood Observatory to the school. The same year, Hale convinced streetcar magnate Charles T. Yerkes to fund what would become, for a time, the largest refracting telescope ever used–40 inches across. The Yerkes Observatory was completed in Williams Bay, WI, in 1897.