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Craters Pop as NASA's Dawn Probe Approaches Ceres

New features on Ceres' icy surface are popping into view as NASA's Dawn spacecraft slowly spirals in on its final celestial target in the asteroid belt.

New features on Ceres' icy surface are popping into view as NASA's Dawn spacecraft slowly spirals in on its final celestial target in the asteroid belt.

ANALYSIS: NASA Spacecraft Ready to Unlock Ceres' Mysteries

Due to arrive in a stable Ceres orbit in March, the ion drive-propelled spacecraft is now less than 90,000 miles (145,000 kilometers) from its ultimate goal.

As the solar system's innermost dwarf planet, very little was known about Ceres until this year's sharpening photographs from Dawn. Before Dawn, only a blurry blob through the Hubble Space Telescope's optics could be seen, with hints of color variations in the small world's surface.

NEWS: NASA Probe Gets Best Ever View of Dwarf Planet Ceres

But as this most recent series of observations show, Ceres has a varied surface apparently covered in impact craters. In the dwarf planet's south polar region, for example, a large, well formed and approximately circular impact crater can be resolved.

The mysterious bright feature that has fascinated planetary scientists is still there and slowly beginning to reveal some detail. What's more, there appears to be several more smaller bright features -- could they be indicative of ice accumulations or some subsurface mineral exposed by impacts?

These are the sharpest images of Ceres to date, where each pixel spans 8.5 miles (14 kilometers) across.

On Monday, Discovery News attended the NASA Jet Propulsion Laboratory's "Icy Worlds" media event in Pasadena, Calif., and had the opportunity to chat with Dawn mission scientists, find out what they had to say about their unprecedented and thrilling mission.

For more information about this observation and the Dawn mission, browse the Dawn news release.

This is an animation of several observations acquired by NASA's Dawn spacecraft on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles (145,000 kilometers) from the dwarf planet.

NASA's Dawn spacecraft orbited the massive asteroid Vesta in 2011 and 2012, giving us an unprecedented look at the protoplanet's landscape, craters and mineral composition. The probe, which is now on its way to dwarf planet Ceres, not only revealed the evolution of Vesta, it also provided vital clues as to the evolution of our solar system. Now,

in new images published by NASA

, an unusually colorful Vesta landscape is on display. Using data from the mission, scientists at Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany have produced a rather psychedelic view of this otherwise bland landscape. Dawn's camera system is equipped with seven filters, each filter sensitive to a specific wavelength of light. Normally, Vesta would look gray to the naked eye, but when analyzing the ratios of light through Vesta's filters, the landscape pops with color. Shown here, the flow of material inside and outside a crater called Aelia is demonstrated. As different minerals reflect and absorb different wavelengths of light, this composite image is alive with color, each shade representing different kinds of minerals littering Vesta's landscape.

This is Antonia, a crater located inside the huge Rheasilvia basin in the southern hemisphere of Vesta. From this image, planetary scientists have been able

to deduce that

"the light blue material is fine-grain material excavated from the lower crust. The southern edge of the crater was buried by coarser material shortly after the crater formed. The dark blue of the southern crater rim is due to shadowing of the blocky material."

The impact crater Sextilia can be seen in the lower right of this image. The mottled dark patches are likely impact ejecta from a massive impact and the redish regions are thought to be rock that melted during the impact. The diversity of the mineralogy is obvious here. "No artist could paint something like that. Only nature can do this," said Martin Hoffman, a member of the framing camera team at Max Planck Institute.

Earlier images of Vesta have shown an unusual "pitted terrain" on the floors of the craters named Marcia (left) and Cornelia (right). Once again, the varied colors demonstrate the different minerals and processes that cover Vesta's surface.

This

"global" model

of Vesta shows the abundance of hydrogen on Vesta's surface. Note that the hydrogen signal is enhanced near the asteroid's equator. The hydrogen is likely from hydroxyl or water bound to minerals in Vesta's surface.

Another, earlier view of Antonia crater, demonstrating the mineral diversity of the region.

This is the distinctive Oppia crater on Vesta, an impact that occurred on a slope. This produced an asymmetric ejecta distribution around the crater -- the red/orange ejecta material is more abundant around the downward slope than around the upward portion.