ALMA Reveals Source of Io’s Atmosphere

18 December, 2020 / Read time: 1 minute

This video shows one of the most important discoveries made by radio astronomy in 2020. On this occasion, the Atacama Large Millimeter/submillimeter Array (ALMA) pointed its antennas at Io, Jupiter's third largest moon, which has a thin atmosphere composed mostly of sulfur dioxide that gives the satellite a yellowish color.

As detailed in the video, this observation sought to discover what proportion of the sulfur dioxide in the atmosphere comes directly from the emission of gases from its 150 active volcanoes, and how much is due to the sublimation of the surface as a consequence of the heat that this moon receives from the Sun.

Credits: National Radio Astronomy Observatory (NRAO)