4074_9550_1 The setting for hellish volcanism, this is the surface of Io as viewed by Galileo, a robotic mission to Jupiter that ended spectacularly in 2003.

Pictured here is the Tvashtar catena, which must be the very definition of "sulfurous". 

For comparison's sake take a look at this image of Io (and Europa) taken by New Horizons - currently en route to a 2015 rendezvous with the tidally locked dwarf bodies Pluto and Charon.

The Tvashtar plume in the linked image reaches 190 miles into space.