Annie Jump Cannon and the Harvard Computers

In 1886, Harvard College Observatory director Edward C. Pickering had a monumental task. Funded by Anna Palmer Draper as a memorial to her late husband, the observatory was creating a photographic map of the night sky's brighter stars. Using a new technique, a single glass plate could capture the spectra of hundreds of stars at once. From Massachusetts and, within a few years, a new southern station in Peru, the observatory began collecting an unprecedented flood of data. The collection eventually grew into a massive archive of hundreds of thousands of plates, each a ghostly image packed with faint stellar fingerprints. But Pickering faced a huge problem: how to analyze them all? He needed a team to meticulously identify, measure, and classify every single star in this vast new archive of the heavens.