In 1993, a strange string of comet pieces was discovered near the planet Jupiter. So unusual a sight, Comet Shoemaker-Levy 9 (SL9) quickly became the object of much scientific curiosity. Studies showed that the Sun would soon perturb the orbit of SL9 so that it would actually strike Jupiter in July 1994. The studies were right. The above picture shows the impact site of SL9's fragment G on Jupiter's cloud-tops. The size of the dark outer ring is roughly the size of the Earth. Since Jupiter is mostly gas, the comet melted and evaporated before plunging too far into Jupiter's atmosphere.