The Role of Sulphur in Io's Volcanoes

Caption NASA originale:"Sulphur gas, consisting of pairs of sulphur atoms (S2) - as detected above Io's volcano Pele by the HST in October 1999 - is ejected from the hot vents of Io's volcanoes (green arrow). Such sulphur gas lands on the cold surface where the sulphur atoms rearrange into molecules of 3 or 4 atoms (S3 and S4) which give the surface a reddish color. In time, the atoms rearrange into their most stable configuration (S8) that forms ordinary pale-yellow sulphur".