Question: We are doing a project on constellations and were wondering if you could answer our question: why do the myths about the constellations correspond with legends from different cultures?
Answer: It was natural for early cultures to see pictures in the arrangement of stars in the night sky. According to the very nice overview of the mythology of constellations compiled by Cathy Bell of Princeton University, texts dating back roughly 6000 years suggest that ancient people saw the forms of a lion, bull, scorpion, and other creatures in the night sky. Over time Greek and Roman culture coupled constellations to mythology, such that by the 5th century the mythical connection to constellations was complete. You can find quite a bit more background on this connection between mythology and constellations in the reference above, including detailed information on the mythology associated with many constellations.