The Mars rover Opportunity is working to free itself from a patch of loose soil it got stuck in on Monday. But rover scientists are hopeful it will escape relatively easily, since it got out of a similar predicament last year simply by spinning its wheels backwards.
The rover was attempting to drive along a trough between the crests of ripples in the Martian soil when it got stuck. But it is not mired as deeply as it was in April 2005, when it was trapped for about five weeks on a 30-centimetre-high ripple of soil, nicknamed "Purgatory Dune".
