NASA’s robotic probe named Dawn has beamed back close-up images of asteroid Vesta, the second most massive object in the Asteroid Belt.

From dusty landslides to towering mountains, the new images reveal unprecedented details of the roughly 328-mile-wide, 4.6-billion-year-old rock.

Planetary scientists have waited nearly four years for Dawn to reach its first target after launching Sept. 27, 2007. The probe is slated to journey to the potentially muddy and icy protoplanet Ceres in July 2012.

Dawn slipped into orbit around Vesta on July 16, 2011 by spitting a steady stream of ions from its engine. Although the probe has returned other images of Vesta since arriving at the space rock, the latest batch of photos, taken from an orbit of 1,700 miles above the asteroid’s surface, are the most detailed yet.

We detail the best shots provided by NASA and its partners in this gallery.

Above:

Counting craters on Vesta’s surface can help planetary scientists figure out their relative ages — and donning 3-D glasses helps them count.

Image: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA [high-resolution version]