<P> This is a list of active, dormant and extinct volcanoes located beyond planet Earth . They may be designated mons (mountain), patera (an irregular crater) or tholus (small mountain or hill) in accordance with the International Astronomical Union's rules for planetary nomenclature . Many of them are nameless . </P> <P> Io, a moon of the planet Jupiter, is the most volcanically active body in the Solar System . Its volcanoes are believed to eject sulfur and sulfur dioxide, as well as basaltic and ultramafic silicate lavas . </P> <P> Mars has many shield volcanoes, including the largest known volcano of the Solar System, but they are all dormant if not extinct . </P>

Lots and lots of volcanic activity in our solar system