Meet the Gods: Saturn     Merry meet. In case you don’t have enough holiday activities in December, you can add the 17th to your calendar and observe Saturnalia, one of the most popular ancient Roman festivals. It occurred around the time of Yule. Though originally a one-day event that ignored the distinction between masters and slaves, the activities came to fill an entire week, making for much merry-making and lechery.     Saturn was the son of Caelus, Father Sky, and Terra, Mother Earth. (In Greek mythology they were Cronus, Uranus, and Gaia, respectively.) To prevent a prophecy from coming true – that a son would dethrone him –…