The celestial sphere were split in constellations in Ancient Times. Constellations were imaginary figures based on human fantasy and similarity with objects, animals, people or mythological figures. Nowadays the division of the sky into constellations is necessary especially for identifying celestial bodies easily. The most famous constellations are the zodiacal constellations. Other well-known constellations are: Cassiopeia, Cygnus, Orion, the Big and Little Dippers, Pegasus.