During the Galileo probe's descent through Jupiter's atmosphere on December 7, 1995, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars.
There is air and water within Jupiter's atmoshere, scientists say. The fact that the Shoemaker-Levy comet was able to kick up dust clouds high into the atmosphere shows this. A planet without much air or no air at all would have a more imploding effect or vacuum effect.