Before modern supercomputers organized the night sky, a nearly deaf astronomer manually charted more stars than anyone else in human history. Born in Delaware in 1863, Annie Jump Cannon was introduced to the constellations in her childhood attic by her mother, Mary Jump, who also taught her chemistry, math, and "household economics"—a discipline that instilled in Cannon a profound talent for managing complex, chaotic inventories. After graduating as valedictorian from Wellesley College in 1884 with a physics degree, Cannon contracted scarlet fever, a devastating illness that left her nearly deaf. Bypassing the social isolation of her hearing loss, she channeled her energy into photography and spectroscopy—the study of dark "absorption lines" that act as the chemical barcodes of starlight—laying the physical and chemical groundwork for her recruit ...