Before NASA's Curiosity rover landed on Mars, the strata exposed in Mount Sharp were compared to those in the Grand Canyon of the western United States, shown here. Now that the rover has arrived, scientists are surprised by just how close the similarities between the two terrains are.

The lower reaches of Mount Sharp form a succession of strata as thick as those exposed in the Grand Canyon, and with a diversity of colors to match, complete with buttes and mesas. The major difference is that the strata of the Grand Canyon are exposed along a great valley, whereas the strata of Mount Sharp are exposed along the flanks of a great mountain.