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Dwarf Planet's Puzzling Landscape Snaps into View

NASA's Dawn probe is slowly closing in on its final destination and new observations of the dwarf planet Ceres are revealing a fascinatingly complex little world.

NASA's Dawn probe is slowly closing in on its final destination and new observations of the dwarf planet Ceres are revealing a fascinatingly complex little world.

VIDEO: Dwarf Planet Ceres is Amazing

"As we slowly approach the stage, our eyes transfixed on Ceres and her planetary dance, we find she has beguiled us but left us none the wiser," said principal investigator Chris Russell, of the University of California, Los Angeles (UCLA), in a NASA news release. "We expected to be surprised; we did not expect to be this puzzled."

These most recent images were acquired on Feb. 12 from a distance of around 52,000 miles (83,000 kilometers) as the robotic spacecraft slowly spirals in on its target. In this highest-resolution ever view of Ceres, each pixel represents 4.9 miles (7.8 kilometers).

IN DEPTH: NASA Spacecraft Ready to Unlock Ceres' Mysteries

As opposed to a rapid deceleration burn that would be carried out by spacecraft using conventional rockets for propulsion (in the case of NASA's Cassini probe, for example), Dawn is taking the slow-yet-steady approach using ion engines. This form of propulsion allows continuous thrust for long periods of time, using tiny quantities of fuel. So rather than flying full-speed at Ceres, Dawn has slowly ‘danced' into formation around Ceres, allowing us many weeks of a gradually sharpening view as the mission creeps up on the solar system's innermost dwarf planet.

Of particular interest to planetary scientists remains the bright patches of landscape - including the one particularly bright feature shown in the image above (right frame). Other bright features are present, but the origin of this discrete spot is keeping astrogeologists guessing.

ANALYSIS: Craters Pop as NASA's Dawn Probe Approaches Ceres

During Dawn's journey through the asteroid belt - the region of space between the orbits of Mars and Jupiter - the Hubble Space Telescope detected plumes of water around Ceres. Could these plumes be associated with geysers leaking a sub-surface ocean of water into space, as observed at Saturn's moon Enceladus and Jupiter's moon Europa? If so, these bright features may highlight venting cracks in Ceres' crust where water is being forced from the dwarf planet's interior, venting to space as vapor and freezing on the surface as an icy residue, appearing as bright patches on the cratered surface.

But as these images are showing, Ceres is covered in craters, suggesting it has an ancient rocky surface, not a continually recycled icy surface like Enceladus of Europa. So perhaps these white areas are signs of cryovolcanism?

For now, this is all speculation, but as dawn approaches Ceres orbit, many of these mysteries will likely soon be revealed.


These two views of Ceres were acquired by NASA's Dawn spacecraft on Feb. 12, 2015, from a distance of about 52,000 miles (83,000 kilometers) as the dwarf planet rotated. The images have been magnified from their original size.

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.


"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.