A year on from the landings of US Mars Rovers, Science devotes much of its early December 2004 issue to findings from the more revealing of the two missions, Opportunity (multi-authored 2004. Opportunity runneth over.  Science, v. 306, p. 1697-1756).  The articles are highly detailed accounts of the main finding from the various instruments aboard Opportunity, including the evidence for the activity of acid waters on the ancient Martian surface.  Equally interesting and considerably more graphic are important findings about volcanic and glacial activity in much more recent times, that come from the European Space Agency’s Mars Express Orbiter and the High Resolution Stereo Camera carried by it (Neukum, G and 42 others 2004.  Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera.  Nature, v. 432, p. 971-979). Recently, excitement about evidence for living organisms on Mars rose with the discovery of significant amounts of methane in the Martian atmosphere.  Methane is likely to have a short life span (around 300 years) in the atmospheres of rocky planets.  There are two possible sources: methane-generating bacteria or release from volcanoes.  The High Resolution Stereo Camera shows conclusively that volcanoes were active on Mars until at least 5 Ma, when previously the planet was thought to be magmatically dead.  If fumarole activity continues, that could explain the traces of methane.