Rover Reward for Climbing: Exposed Geological Contact

The Martian outcrop where pale rock meets darker overlying rock near the middle of this view is an example of a geological contact. Such contacts can reveal clues about how the environmental conditions that produced one type of rock were related to the conditions that produced the other.

NASA's Curiosity Mars rover took this image with its Navigation Camera (Navcam) just after finishing an uphill drive of about 72 feet (22 meters) on the 991st Martian day, or sol of the rover's work on Mars (May 21, 2015).

http://photojournal.jpl.nasa.gov/catalog/PIA19663