With all the buzz the SUV-sized Curiosity rover has generated since it landed on Mars in 2012, it's easy to forget that the rover has a little sister, named Opportunity. The smaller, golf-cart size rover has been exploring the Martian rilles and plains since January of 2004, and rarely gets much of a rest. Even when it does, it makes good use of its downtime.
In June, mission controllers parked Opportunity for two weeks while they worked to resolve a problem in the rover's front left wheel, which was stuck at an outward-pointing 30 degrees. As it happened, the parking spot the controllers chose was on the western rim of what Martian cartographers have dubbed Endeavour Crater, looking down over Perseverance Valley. The heroic names live up to the stark beauty of the scene, as images the rover beamed home attest.
In the foreground, Opportunity's wheel tracks vanish over a notch in the crater's rim, which may have been carved by water or ice, back in the long-ago era when Mars fairly sloshed with seas, rivers and oceans. The crater itself may have thus been a great body of water.
The pictures were taken by the rover's two-eyed Pancam and were captured in three kinds of light. The first image shows the crater as it would look to a human being standing with Opportunity; the second combines the views of the two Pancam perspectives to create a 3D effect. In the third image, artificial color has been added to designate different types of surface material.
Opportunity also threw in a couple of black-and-white selfies — one of its own shadow cast on the ground, and the other shot by its navigation camera, as the rover descended the crater's rim and the camera looked backward at where it had been. Even after 13 years on the Martian surface, however, Opportunity itself is still looking ahead.