Mount Sharp

The main target of NASA's Curiosity rover has always been Mount Sharp, a three mile high mountain in the middle of Gale Crater.  Scientists theorized Sharp had been built over time by sedimentary layering, and examining those layers up close could tell a lot about Mars' geological history.

A new study, however, suggests Sharp was not shaped by layering-- which would involve water-- but by wind whistling down the crater walls.  When Curiosity reaches the mountain its investigations will be able to determine which theory is correct.