After being stuck in a sand ripple for the past five weeks, the Mars Rover Opportunity was finally able to free itself. Opportunity became stuck on April 26 on the way to study an impact crater.

Rover looking back at its tracks: Courtesy NASA/JPLCourtesy NASA/JPL

Now that it is free, Opportunity will take a closer look at the area it became stuck in to determine what made the sand ripple it was stuck in any different from the dozens of others it had driven over in the past with no incidence. Hopefully this will enable the rover to avoid being stuck again.

Meanwhile Spirit, Opportunity's twin, captured several images of dust devils as they cross the surface of a crater.

Opportunity and Spirit, have been exploring the Mars surface for over a year, far longer than the three month mission that was originally planned.