The anticipated triple hit on Jupiter got some added cosmic oomph as a fourth shard of the disintegrating Shoemaker-Levy 9 comet smacked the planet with the other three. Q1 hit just before its separated twin, Q2, collided in nearly the same spot. Fragments R and S landed during the following 20 hours. The four fell within 100 miles of one another on the solar system's largest planet. The effect: four giant fireballs and overwhelming heat. COMET COUNTDOWN: Four more fragments to go. The last will land on Jupiter tomorrow.