Astronomy Picture of the Day

Explanation: What are those unusual looking dimples? Looking back toward Eagle crater, its landing place on Mars, the robot rover Opportunity has spotted some unusual depressions in the Martian soil. The dimples, visible above on the image left, each measure about one metre across and appear to have light coloured rock in their interior. The nearest dimple has been dubbed "Homeplate", while the next furthest one out is called "First Base." Scrolling right will reveal a magnificent panorama including the rover in the foreground, the backshell and parachute that detached from Opportunity before it landed near the horizon, Eagle crater in the centre, Opportunity's tracks as it rolled away from Eagle crater, and wind blown ripples of Martian soil in every direction. Further analysis of rocks photographed by Opportunity has yielded evidence that Opportunity has landed on an evaporated shoreline of an ancient salt-water ocean.