CAL TECH SCIENTISTS have announced they’ve discovered the tenth planet of the solar system. The find, if it becomes generally accepted and acknowledged as a “real” planet instead of just a big rock, would fulfill the prophecies of 20th-century astrologers who posited a tenth planet as necessary to make their calculations work out. When Daffy Duck went to explore “Planet X,” he was off to the roman-numeraled world of the astrologers’ theories.