Shoemaker-Levy 9 supplied almost all of aqueous part of the planet's upper atmosphere
In July 1994, the comet Shoemaker-Levy 9 plowed into Jupiter, and the comet fragments triggered dark scars of debris in the giant planet’s atmosphere that were visible for weeks. The comet also left behind a more permanent deposit: millions of gallons of water. Water from the impact still makes up at least 95 percent of the water in the planet’s upper atmosphere, researchers report April 23 in Astronomy & Astrophysics.
Telescopes had previously spotted water in Jupiter’s upper atmosphere, some 100 kilometers above the planet’s ammonia cloud