Twins of the Sky-Gemini-

The ancient Greek tale of the egg-born brothers Castor and Pollux, born to their mother Leda after she was seduced by Zeus in the guise of a swan. Their consummation, on the same night as Leda lay with her husband, Sparta's King Tyndareus, resulted in the birth of immortal Pollux, who possessed great physical strength, and mortal Castor who possessed great ingenuity. Upon Castor's death Pollux begged Zeus to let him share his own immortality with his twin to keep them together and they were transformed into the Gemini constellation.