MULTIMEDIA

This composite-color view from NASA's Dawn mission shows Cornelia Crater, streaked with dark materials, on the giant asteroid Vesta.

These mosaic images show how dark, carbon-rich materials tend to speckle the rims of smaller craters or their immediate surroundings on the giant asteroid Vesta.

This map shows the distribution of dark materials throughout the southern hemisphere of the giant asteroid Vesta.

This image shows examples of long, narrow, sinuous gullies that scientists on NASA's Dawn mission have found on the giant asteroid Vesta.

This image shows a close-up of long, narrow, sinuous gullies that scientists on NASA's Dawn mission have found on the giant asteroid Vesta. The crater shown here is called Cornelia.

This image shows examples of straighter, shorter, wider gullies that scientists on NASA's Dawn mission have found on the giant asteroid Vesta. The crater shown here is called Fonteia.

This image of Fresh and Bright Canuleia from NASA's Dawn spacecraft features the distinctive crater Canuleia on the giant asteroid Vesta.

This image from NASA's Dawn spacecraft shows a close up of part of the rim around the crater Canuleia on the giant asteroid Vesta.

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of "pitted terrain," an unexpected discovery in data returned by the Dawn mission.

This map from NASA's Dawn mission shows the global distribution of hydrogen on the surface of the giant asteroid Vesta.

Hydrogen is most abundant in areas with low reflectivity, or albedo, on the giant asteroid Vesta, as shown in this contour map from the Dawn mission.

This perspective view of Cornelia crater on the giant asteroid Vesta shows an example of "pitted terrain," an unexpected discovery in data returned by the Dawn mission.