The constellation of Cancer, the "Crab" is an undefined grouping of faint stars in an area between Gemini and Leo. It is an ancient constellation, although why it should have been given such prominence is not known, perhaps early astrologers created the asterism to fit in with their theories that the monthly movement of the Sun through various constellations had some bearing on Earthly life. Legends abound regarding this little creature; the Greeks thought the crab came to the assistance of Zeus when he wrestled with his brother Poseidon for mastery of the Earth. Poseidon killed the crab, whereupon a victorious Zeus rewarded it with a place in the heavens. It also features in the myth of Orion and that of Hercules as an unfortunate creature sent by Hera to antagonize the heroes, but being killed and placed in the sky.