Traditionally associated with the crab in ancient Greek mythology, Cancer's story originates from Heracles (Hercules), who battled the Hydra in the Lernaean War—a giant multi-headed serpent sent by the goddess Hera to destroy him. Despite Hera's efforts, Heracles emerged victorious. In her anger, Hera sent a giant crab to aid the Hydra, but Heracles defeated both creatures. Impressed by the crab's bravery, Hera placed it in the sky as the constellation Cancer.

The stars of the Cancer constellation are situated near the Beehive Cluster, also known as "Praesepe." In modern astronomy, Cancer showcases several interesting spiral galaxies and star clusters worthy of observation. The uniqueness and mythology surrounding this constellation have made Cancer a focal point of stories and research throughout human astronomical history.