Gemini, the Twins (Castor, Alpha, represented by the bright star at upper right of the figure, and Pollux, Beta, by the star at lower left), from Bayer's Uranometria of 1603. The horizontal dashed line is the ecliptic. Cancer, the Crab, is immediately to the left of Gemini. The upper left part of Orion is down and to the right, Canis Minor and Procyon are beneath the Twins, while the head of Hydra, the Water Serpent, is to the lower left. The broad dark band at the top is centered on the ecliptic, and shows the region in which the Moon and planets can be found. The Milky Way runs at right across the Twins' feet.

Courtesy of the Rare Book Room and Special Collections Library of the University of Illinois