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This is an image of Io.
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The Jet Propulsion Laboratory

Io's Atmosphere

There are no clouds and lightning. The atmosphere of Io is very thin and does not remain gravitationally bound to Io for very long. Even so, it has an important impact on the Jupiter system.

Io's atmosphere comes from its volcanoes, then disperses because, as a small moon, Io is not massive enough to have substantial gravity. Portions of the atmosphere may also come from other processes which cause molecules to be extracted from the surface.

Because the atmosphere comes from it's volcanos, the air of Io is made primarily of sulphur.

Once the particles from the atmosphere get into the magnetosphere, they create a donut-shaped cloud of material around Io.

The Galileo spacecraft, in exploring the moons of Jupiter will try to learn more about the atmosphere of Io.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA