A sharp-eyed camera on the Opportunity rover has beamed home the best images yet of the rugged rim of Endeavour crater, the robot's next destination on its tour of the windswept plains of Mars.

This super-resolution image from the Opportunity rover is labeled with proposed names of features on Endeavour crater's rim. Credit: NASA/JPL-Caltech/Cornell University

Now in its seventh year on Mars, the rover has completed a third of a bold 12-mile traverse to Endeavour crater, the largest impact site ever visited by a lander on the Red Planet.

The rover is still more than 7 miles from Endeavour crater, but Opportunity is now driving on a gentle slope offering a view of the crater's rim, according to NASA.

Opportunity gathered the images for the sharp mosaic on May 12. NASA released the picture Tuesday.

NASA used an imaging enhancer to create a super-resolution picture of the crater's edge. Super-resolution is a technique that combined multiple frames from the rover's panoramic camera into a single image with improved resolution.

The super-resolution picture shows the western flank of Endeavour's rim. A thick blanket of ejecta material from a nearby crater lies beyond the crater wall.

Rover scientists have already started giving crater features informal names under a theme of places visited by British Royal Navy Capt. James Cook during his exploration of the Pacific Ocean aboard the HMS Endeavour.

This image from the Mars Reconnaissance Orbiter's context camera shows Opportunity's position (left) in relation to Endeavour crater and the landmarks from the rover's super-resolution picture. Credit: NASA/JPL-Caltech/Malin Space Science Systems

The asteroid or comet that formed Endeavour crater carved a hole into Meridiani Planum nearly 14 miles across and 1,000 feet deep.

Scientists are eager to get an up-close view of the crater because it harbors exposed clay minerals, which formed in ancient watery environments that were potentially suitable for life.

An instrument on the Mars Reconnaissance Orbiter discovered the clay minerals, and researchers reported the finding in 2009. Clay minerals on Mars have never been analyzed from the surface before, so scientists are carefully mapping the distribution of clay to pick the most promising site to visit first at Endeavour.

Earlier this month, Opportunity's odometer clicked past 13 miles since landing in January 2004.