Comet Shoemaker–Levy 9 about 50 arcseconds long and 10 arcseconds wide. Brian G. Marsden of the Central Bureau for Astronomical Telegrams noted that the comet lay only about 4 degrees from Jupiter as seen from Earth, and that although this could of course be a line of sight effect, its apparent motion in the sky suggested that it was physically close to it. Because of this, he suggested that the Shoemakers and David Levy had discovered the fragments of a comet that had been disrupted by Jupiter's gravity. Orbital studies of the new comet soon revealed that it was orbiting Jupiter rather than
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