Fish are always trying to fend off other creatures, from other fish to birds to people. That applies to fish that are in the stars as well. In fact, the southern fish, Piscis Austrinus, has been nibbled at several times over the centuries. The constellation was established in ancient Babylon. Later, it was adopted by the Greeks, who tweaked its mythology. They said that a goddess either fell or threw herself into a river. She was rescued by a fish, which was placed in the heavens as a reward. The original constellation was a stick-figure outline anchored by Fomalhaut, the fish’s only bright star. Later, astronomers began shifting things around. The star that originally represented the fish’s tail, for example, became the head of the new constellation Grus, the crane. Some stars that one astronomer assigned to the fish were later moved by other astronomers. They became part of a constellation that honored the microscope. Today, the constellation has precisely defined borders. That keeps
