NASA has released new images of the dwarf planet Ceres, created using data from the Dawn spacecraft. They reveal the varied topography of this intriguing world – while the agency has also sought help from the public to understand some of its more mysterious features.
The images use false colors to highlight different compositions on the surface. Red shows areas that strongly reflect infrared light, blue represents shorter (bluer) wavelengths, and green areas are the brightest (highest albedo) parts of the surface. Without this false-color view, Ceres looks fairly homogenously gray to the naked eye.
Using this technique, one image shows the fascinating Occator crater, home to the brightest of Ceres' bright spots. The origin of these features remains a mystery, with ice or salt flats among the favored theories at the moment. Another image shows a puzzling cone-shaped mountain towering 6 kilometers (4 miles) above the surface, but how it came to be is unknown.
This map shows the entire surface of Ceres in false color. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
To better understand Ceres, NASA has welcomed help from the public. One amateur enthusiast, for example, sent Dawn’s principle investigator Christopher Russell, from the University of California, Los Angeles an email saying the mountain looked similar to ice structures seen in woods in Arkansas.
"Maybe our lonely mountain was some sort of ice construct," said Russel at the European Planetary Science Congress in Nantes, France, reported AFP. "We're taking suggestions like this very seriously."
The craters themselves on Ceres are interesting as they are not bowl-shaped, like on Dawn’s previous target, Vesta. Instead they are irregularly shaped, more akin to Saturn’s icy moon Rhea. An instrument on Dawn also captured an “unexpected observation,” according to Russell – three bursts of energetic electrons, possibly from the interaction of Ceres and the Sun.
The origin of this conical mountain on Ceres remains a mystery. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.
Dawn is continuing to lower its orbit around Ceres – it is currently at an altitude of 1,470 kilometers (915 miles), but will descend to its lowest and final orbit in December, just 375 kilometers (230 miles) above the surface.
"Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts," said Russell in a statement.