NASA’s Curiosity Mars Rover is currently exploring a location called “Windjana,” where the rover found rocks containing manganese-oxide minerals, which require abundant water and strongly oxidizing conditions to form.
Winjana is within a site called “The Kimberley,” where sandstone layers with different degrees of resistance to wind erosion are exposed close together.
In front of Curiosity are two holes where the rover drilled to collect samples of rock powder from the interior of the rock. The holes are 0.63 inch (1.6 centimeters) in diameter. The hole is surrounded by grayish cuttings on top of the rock ledge to the left of the rover.
These features are erosion-resistant fracture fills containing manganese oxides. The discovery of these materials suggests the Martian atmosphere might once have contained higher abundances of free oxygen than it does now.
The rover used the camera at the end of its arm to take dozens of component images combined into this self-portrait.