Dust Devil...

On Mars, that is.  This image was captured by Opportunity, still hard at work on the surface of Mars, 6.5 years after its 90 day mission “ended”.  This is the first dust devil seen by Opportunity.  It's twin Spirit, halfway around the planet, has seen dozens of them. 

Winter is just ending in Spirit's part of Mars, and NASA has not yet heard from it since it shut down to “hibernate” for the winter.  It may be the end of the line for Spirit; the reports from NASA don't sound very optimistic.  The main problem was that it got stuck in one place of soft soil (probably resting its belly on a rock), and couldn't move to a nice, sunny spot for the winter...