Both Spirit and Opportunity are still suffering under incredibly dark skies, but, amazingly, they are both "power-positive," meaning that they are managing to produce enough power from the limited amount of sunlight to keep the batteries fully charged.
Today's set of image releases from the Mars Reconnaissance Orbiter HiRISE team included this one, of a fairly bland-looking lava plain to the northeast of Arsia Mons. Bland, that is, except for a black spot in the center.
It's easy to forget that Mars is another such world with cloudy weather and seasonally varying climate. This lovely image release from the CRISM instrument on Mars Reconnaissance Orbiter brings that point home.