Currently it is northern winter on Vesta, and the northern polar region is in perpetual darkness.
Vesta and Ceres are the two most massive objects in the main asteroid belt.
It was originally classified as a eucrite, a group of meteorites thought to be from the asteroid Vesta.
One in every 20 meteorites that strikes Earth is a piece of Vesta.
The Dawn probe was launched in 2007 and has already sent back dramatic pictures from the giant asteroid Vesta.
The JPL has also released a video with more images from Vesta and some interesting info about the Dawn mission.
It will linger at Vesta, the second most massive object in the asteroid belt, until next summer, when it is scheduled to depart for a larger asteroid called Ceres.
Unlike any other asteroid known today, Vesta has an iron core surrounded by layers of mantle rock and crust, similar to Earth and Mars, preliminary gravity and density measurements suggest.
Moreover, Vesta may have survived intact from the solar system's origin, despite having been pummeled by impacts so violent that they sprayed the solar system with buckshot blasts of debris.
"Vesta is so rich in features that it will keep the science team busy for years, " said mission scientist Holger Sierks at Germany's Max Planck Institute for Solar System Research.
NASA's current interest in Vesta, however, is entirely scientific.
"Dawn's crowning success at Vesta was the delivery of instruments that require proximity, exemplified by the gamma-ray and neutron measurements of Prettyman et al. yielding elemental abundances that unequivocally confirm the meteorite links, " Binzel wrote.
The probe entered a special low-altitude orbit for about five months to allow the GRAND instrument to analyze emissions from Vesta's surface that result from collisions between cosmic ray particles and elements in the asteroid's dirt.
The probe, which launched in 2007, reached Vesta a few weeks ago, and will be spending about a year there before it departs on its three year journey to the dwarf planet Ceres, also located in the asteroid belt.
Preliminary mapping data show that Vesta is a world layered in many different rock types and minerals, supporting the notion that it might have become a major planet had it not been trapped in the asteroid belt's powerful gravitational rip tides.
This finding ties in with the revelation of hydrogen on Vesta, because the likeliest explanation for the indentations on the surface is that hydrogen, which is likely bound up in minerals there, is released in the form of water vapor when the material is heated up by impacts.
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