Overlooked treasure—the first evidence of exoplanets

Beneath an elegant office building with a Spanish-style red tiled roof in Pasadena, California, three timeworn storerooms safeguard more than a century of astronomy. Down the stairs and to the right is a basement of wonder. There are countless wooden drawers and boxes, stacked floor to ceiling, with telescope plates, sunspot drawings and other records. A faint ammonia-like smell, reminiscent of old film, fills the air.