A gathering storm.

The article discusses dust storms on the planet Mars that were detected in mid-March 2009 and their regularity when Mars makes its closest approach to the sun. It notes that the dust impedes the imaging capabilities of orbiting spacecraft including the Mars Reconaissance Orbiter, Mars Odyssey, and Mars Express. It adds that storm-generated dust reduces solar energy available at the planet's surface, throttling back power available to the Spirit and Opportunity rovers.