Astronomers combined 146 exposures taken by NASA's Hubble Space Telescope to make this 73-frame movie of the asteroid Vesta's rotation. Vesta completes a rotation every 5.34 hours.
Hubble's Wide Field Camera 3 observed the potato-shaped asteroid in preparation for the Dawn spacecraft's visit in July 2011. The telescope's sharp "eye" can see features as small as about 25 miles (40 kilometers) across in the images used to construct the movie.
The movie shows the difference in brightness and color on the asteroid's surface. These characteristics hint at the large-scale features that the Dawn spacecraft will see when it arrives at the potato-shaped Vesta.
The asteroid is somewhat like our Moon, with ancient lava beds (the dark patches) and powdery debris, the pulverized remains of impacts (the orange-colored areas). A flattened area on one end of Vesta is a giant impact crater formed by a collision billions of years ago. The crater is 285 miles (460 kilometers) across, close to Vesta's roughly 330-mile (530-kilometer) diameter. The asteroid is about the size of Arizona.
Vesta is one of the largest of a reservoir of about 100,000 asteroids, the leftover material from the formation of our solar system's planets 4.6 billion years ago.
Astronomers combined images of Vesta in near-ultraviolet and blue light to make the movie. The Hubble observations were made on Feb. 25 and Feb. 28, 2010.