Atmosphere of Jupiter Atmosphere of Jupiter The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made of molecular hydrogen and helium in roughly solar proportions; other chemical compounds are present only in small amounts and include methane, ammonia, hydrogen sulfide and water. Although water is thought to reside deep in the atmosphere, its directly measured concentration is very low. The nitrogen, sulfur, and noble gas abundances in Jupiter's atmosphere exceed solar values by a factor of about three. The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the
Atmosphere of Jupiter particles coming from Jupiter's magnetosphere create bright auroral ovals, which encircle the poles. Unlike their terrestrial analogs, which appear only during magnetic storms, aurorae are permanent features of Jupiter's atmosphere. The thermosphere was the first place outside the Earth where the trihydrogen cation () was discovered. This ion emits strongly in the mid-infrared part of the spectrum, at wavelengths between 3 and 5 μm; this is the main cooling mechanism of the thermosphere. <div style="float: right; margin-left: 1em; width: 25em;"> The composition of Jupiter's atmosphere is similar to that of the planet as a whole. Jupiter's atmosphere is the most