Atmosphere of Io
thin layer of gases surrounding Jupiter's moon Io
The atmosphere of Io is the extremely thin blanket of gases surrounding Jupiter's third largest moon Io. The atmosphere is primarily composed of sulfur dioxide (SO2), along with sulfur monoxide (SO), sodium chloride (NaCl), and monoatomic sulfur and oxygen. Dioxygen is also expected to be present.
Origin
Io is considered to be the most volcanically active body in the Solar System. Pele type volcanism is believed to be the cause of sulfur components in the atmosphere. Volcanic plumes pump 104 kg of SO2 (sulfur dioxide) per second into Io's atmosphere on average, though most of this is deposited back onto the surface. Sunlight sublimates this solid SO2, turning it into the gaseous state and creating a thin atmosphere. Due to this, atmospheric pressure is significantly higher near volcanoes, about 0.5 to 4 mPa (5 to 40 nbar), around 5,000 to 40,000 times larger than that of the night side of Io.
Apart from this, minor components like NaCl, SO, O are also formed by other processes. The main source of NaCl and KCl is thought to be volcanic.
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This entry incorporates text from “Atmosphere of Io” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.