Gallery: NASA releases first closeups of asteroid

This view of the dark side of Vesta was taken from a distance of about 3,200 miles.

NASA describes the instruments brought aboard Dawn:

"In addition to the framing camera, Dawn's instruments include the gamma ray and neutron detector and the visible and infrared mapping spectrometer. The gamma ray and neutron detector uses 21 sensors with a very wide field of view to measure the energy of subatomic particles emitted by the elements in the upper yard (meter) of the asteroid's surface. The visible and infrared mapping spectrometer will measure the surface mineralogy of both Vesta and Dawn's next target, the dwarf planet Ceres."

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Here's an image of the south pole of Vesta.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

This set of three craters is in the northern hemisphere of Vesta. They've been nicknamed "Snowman."

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The south equatorial region shows some interesting craters.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The south polar region and its large bump is shown by Dawn days before it arrived at Vesta.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Here's the size of Vesta compared to the 8 other asteroids that humans have made close contact with.

One of Dawn's first images of Vesta on its approach shows the large bump on its surface.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Vesta's equatorial region is marked by grooves.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

This is what Vesta looks like from Earth courtesy of the Hubble Space Telescope.

This should give you an indication of the size of the Dawn spacecraft as scientists prepared it for launch.

Here is the Dawn spacecraft with its ion propulsion system installed.

The ion propulsion system goes through a test on Earth. Dawn has three 30-centimeter-diameter (12-inch) ion thrust units. It produces an electrical charge to accelerate ions from xenon fuel that will be 10 times faster than chemical fuel.

The spacecraft uses only 10 ounces of fuel per day and would accelerate on an Earth highway from 0 to 60 miles per hour in 4 days. But without gravity in space, its got speed to burn.

Here's what the Dawn spacecraft must look like with its solar panels fully extended as it orbits Vesta.

Dawn's next target will be the dwarf planet Ceres - seen here through the Hubble.