In the late 1970s and early 1980s, a quiet revolution was unfolding in the way we see the universe. Astronomers were no longer content with counting galaxies as distant smudges of light on photographic plates. They wanted to map their positions in three dimensions to reveal the true architecture of the cosmos. They wanted an atlas of the heavens. And among those leading this charge to become cosmic cartographers were two American astronomers, Margaret Geller and John Huchra.