NASA has just released a stunning new topographic map of Ceres, the other dwarf planet astronomers are getting to study up close and personal this summer. Unlike Pluto's freakishly smooth and youthful surface, Ceres's exterior is riddled with craters, creating a battered old landscape of peaks and valleys.
The topo maps shown here, with low lying regions indicated in indigo and peaks in red, were constructed by analysing images taken with the Dawn spacecraft's framing camera from a series of different sunlight and viewing angles. The map at the upper left is centered on terrain at 60 degrees east longitude, while the right view is centered around 240 degrees east. The cartesian map below is a simple cylindrical projection of the entire surface.
Included on the map are brand new, International Astronomical Union-approved names for some of the craters and other surface features. (Here's the full list.) As per scientific tradition, Ceres is now speckled with references to mythological spirits and deities. Occator, the 60 mile across, 2 mile deep crater containing those endlessly puzzling bright spots, is named for the Roman agricultural god of harrowing. A smaller bright crater, formerly the unassuming "Spot 1," now goes by the appellation "Haulani," referencing a Hawaiian plant goddess. Then we've got Dantu, after the Ghanaian god of planting corn, and Ezinu, the Sumerian goddess of grain. I'm starting to wonder if NASA has some secret space farming aspirations.
Ceres, with a diameter of only 548 miles, is about 40% the size of Pluto and the largest object in the main asteroid belt located between Mars and Jupiter. NASA's Dawn spacecraft has already spotted many fascinating features on the icy little beast's surface, including landslides and canyons that hint at a geologically active past. Indeed, it's believed that Ceres may once have harbored a massive, geothermally-heated subsurface ocean. Today, most of Ceres' remaining water is locked up in an icy outer shell:
"The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres. The features are pretty consistent with an ice-rich crust," said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
Dawn is currently spiraling toward Ceres, and will be entering its third orbit, three times closer than its previous one, in mid-August. Positioned a mere 900 miles over the dwarf planet's surface, Dawn will continue to take images and collect spectral data, hopefully unravelling the origin of those winking bright spots, and teaching us more about this strange little world's past. Stay tuned!
Top image via NASA/JPL-Caltech/UCLA/MPS/DLR/IDA