Dawn reveals Ceres’ diverse surface features
VIENNA, AUT. — At the 2015 General Assembly of the European Geoscience Union, a new color map of dwarf planet Ceres was released, revealing the diversity of surface features on this planetary body. Variations in surface morphology and color gives evidence that Ceres was once an active body. NASA’s Dawn spacecraft entered into orbit around Ceres’ in March.
“This dwarf planet was not just an inert rock throughout its history. It was active, with processes that resulted in different materials in different regions. We are beginning to capture that diversity in our color images,” said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.
NASA’s Dawn mission made history and became not only the first mission to reach a dwarf planet, but also the first to orbits two objects in the main asteroid belt. Dawn inserted itself into orbit around Ceres’ on March 6, 2015. Prior to that, from 2011-2012, Dawn orbited and studied Vesta, the second largest body in the asteroid belt. The mission uncovered numerous insights about Vesta’s geology and history. In comparison, Vesta is a dry body and Ceres is believed to be 25 percent water ice by mass. By studying both Vesta and Ceres, scientists hope to better understand how the Solar System formed.
Ceres’ is thought to be a protoplanet, whose development was halted by neighboring Jupiter. Its surface is heavily cratered, as expected, but what surprised researchers is the presence of fewer than anticipated large craters. On its surface also appears to be two puzzling bright spots (region 1 and region 5). Located in the northern hemisphere, more details on these spots should be available once Dawn begins its first science phase on April 23, when the spacecraft will be at a distance of 8,400 miles (13,500 kilometers) from the surface, indicated Martin Hoffmann, investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany.
Dawn‘s visible and infrared mapping spectrometer (VIR) is an imaging spectrometer capable of observing the dwarf planet in both visible and infrared light. VIR has been analyzing the relative temperatures of different surface features on Ceres and preliminary data indicates that the multiple bright spots on Ceres’ surface behave differently.
Thanks to observations from NASA’s Hubble Space Telescope, scientists have identified as many as 10 different bright regions on the surface of Ceres. A pair of bright spots, which are by far the brightest visible marks on Ceres, appear to be in an area of uniform temperature, meaning the spots do not differ much from their surroundings. However, another bright spot is in an area much cooler than the rest of Ceres’ surface.
The bright spots have captured the attention of both the public and scientists worldwide, yet their origins remain a mystery. As Dawn gets closer to the surface of Ceres, more images and data will be available. Current data shows the brightest pair of bright spots is located in a 57 miles (92 kilometers) wide crater.
“The bright spots continue to fascinate the science team, but we will have to wait until we get closer and are able to resolve them before we can determine their source,” Russell said.
Ceres and Vesta are both located in the main asteroid belt between Mars and Jupiter. The Dawn spacecraft will continue studying Ceres through June 2016.
Video courtesy of NASA / Kennedy Space Center
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