About

The Harvard Plate Stacks is home to the Harvard College Observatory’s Astronomical Photographic Glass Plate Collection—the largest and most comprehensive collection of its kind in the world. The foundation of this collection was established in 1886 through the generous support of Anna Palmer Draper and the creation of the Henry Draper Memorial.

Today, the collection encompasses more than 550,000 glass plate negatives and spectral images, photographs, archival materials, and ephemera spanning over a century of observations from both the Northern and Southern Hemispheres. Together, these plates preserve the first complete photographic record of the visible universe and contain irreplaceable scientific data that continues to inform research today.

The collection was built, maintained, and studied by hundreds of women, often referred to as the “Women Astronomical Computers.” Their meticulous work led to groundbreaking discoveries and pioneering contributions that shaped modern astronomy. The Harvard Plate Stacks is dedicated to preserving this legacy and making the stories of these women more accessible while advancing new research through the continued study and digitization of this unparalleled scientific and historic resource.

The Harvard Plate Stacks is a Harvard research collection at the Harvard College Observatory, a member of the Center for Astrophysics | Harvard & Smithsonian.