El Capitan is a layered rock outcrop found within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars, this geological outcrop was first discovered and observed by the Mars Exploration Rover Opportunity in February 2004. The rock outcrop was named for El Capitan, a topographical mountain lying within the state of Texas.
See also List of rocks on Mars Eagle (crater) List of surface features of Mars imaged by Opportunity
External links Nasa's Mars Exploration Program