A Comet Makes a Splash

This infrared image of a 33 000‐kilometer‐wide ring of hot gas expanding at 4 km / sec shows the aftereffect of the impact of fragment G of comet Shoemaker‐Levy 9 with Jupiter on 18 July. The ring is apparent at 3.42 microns (shown green) as are Jupiter's two polar hoods. This composite, from Peter McGregor and Mark Allen (Australian National University), also contains infrared images at 3.09 mm (blue) and 3.99 mm (red).