Comet Shoemaker–Levy 9 then fell to below pre-impact temperatures 2–3 weeks afterwards, before rising slowly to normal temperatures. SL9 is not unique in having orbited Jupiter for a time; five comets, (including 82P/Gehrels, 147P/Kushida–Muramatsu, and 111P/Helin–Roman–Crockett) are known to have been temporarily captured by the planet. Cometary orbits around Jupiter are unstable, as they will be highly elliptical and likely to be strongly perturbed by the Sun's gravity at apojove (the furthest point on the orbit from the planet). By far the most massive planet in the Solar System, Jupiter can capture objects relatively frequently, but the size of SL9 makes it a
Shoemaker (lunar crater) named Mawson (after the Antarctic explorer Douglas Mawson). It was officially named Shoemaker in honor of Eugene Shoemaker, the geologist whose remains were on board the Lunar Prospector spacecraft that impacted this crater floor. This crater became of interest to scientists when the Lunar Prospector detected unusually high concentrations of hydrogen on the floor of this and other nearby craters using a neutron spectrometer. The floor of this crater is kept in permanent shadow from the Sun, and thus maintains a temperature below . Thus the floor forms a cold trap, and any molecules of water that wander into the