Opportunity was a NASA Mars rover, part of the Mars Exploration Rover mission, that landed in Meridiani Planum on January 25, 2004. Originally designed for a 90‑sol mission, it operated for nearly 15 years—more than 5,000 sols—traversing over 45 km and providing strong evidence that Mars once held liquid water. It ceased communications after a global dust storm in June 2018 and was declared complete in February 2019.
Source: science.nasa.gov
24/03/2004

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 meter across and appear to have light colored 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 center, 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.