The color map from Dawn reveals a highly diverse body that was active in the past and may still be active today, researchers revealed when the map was unveiled at a science session at the 2015 General Assembly of the European Geosciences Union in Vienna, Austria.
Images from Dawn’s framing camera show a highly cratered body replete with “differences in morphology and color” spread across the surface, the researchers concluded.
“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.
Several intriguing and as yet unexplained bright spots also dot the surface.
“There is no analog to this visual phenomena in the solar system,” Russell told AmericaSpace.
“When we understand it better we may find an analog that displays itself differently. But this is a total surprise. Right now it seems to be unique!”
Dawn made history in March when it simultaneously became the first probe from Earth to reach Ceres as well as the first spacecraft to orbit two extraterrestrial bodies.
It had previously visited Vesta. After achieving orbit in July 2011, Dawn became the first spacecraft from Earth to orbit a body in the main Asteroid Belt, located between Mars and Jupiter.
The probe remained in orbit around the rocky world for an extended mission of 14 months, yielding reams of bonus science images and spectral data for the research teams until departing in September 2012. Vesta is a dry world.
After an interplanetary voyage of some 2.5 years and achieving orbit, the ship flew on its planned trajectory on the dark side of Ceres—the side facing away from the Sun. It reached a maximum altitude of 46,800 miles (75,400 kilometers) on March 18 based on the spacecraft’s momentum.
Dawn is descending toward the first planned science orbit, which will be 8,400 miles (13,500 kilometers) above the surface. After it arrives on April 23, the spacecraft starts the first “intensive prime science campaign,” says NASA.
The first images from the dark side are crescent views taken on April 10 and April 14.
The north pole of Ceres was glimpsed on April 10 in its highest resolution yet. The view is shown herein and taken from a distance of 21,000 miles (33,000 kilometers).
The solar-powered probe was approximately 38,000 miles (61,000) kilometers distant at the moment it slipped into orbit around Ceres on March 6.
In sharp contrast to Vesta, Ceres is an icy world.
Scientists believe that Ceres may harbor an ocean of subsurface liquid water as large in volume as the oceans of Earth below a thick icy mantle—despite its small size—and thus could be a potential abode for life. Overall Ceres is estimated to be about 25 percent water by mass.
Dawn’s images obtained thus far reveal Ceres to be a pockmarked world with craters of many sizes.
Ceres is a huge and mysterious alien world the size of Texas. It measures approximately 590 miles (950 kilometers) in diameter and is nearly round.
It is the largest and most massive object in the main Asteroid Belt, which lies between Mars and Jupiter. Vesta is the second most massive object in the asteroid belt.
Both are fossil remnants dating back to the formation of our Solar System. Exploring the difference between the two will help elucidate our understanding of the origin and evolution of our Solar System.
Today, Ceres features a remarkable collection of perhaps 10 or more bright spots. The brightest are a duo of dauntingly mysterious bright spots smack dab in the middle of a 57 miles (92 kilometers) wide crater that look like a pair “eyes.”
The bright spots have not yet been resolved in the camera images. They will be resolved soon, now that Dawn is spiraling down in altitude ever closer toward the surface.
“More detail will emerge after the spacecraft begins its first intensive science phase on April 23,” said Martin Hoffmann, investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany.
The bright spots are reflected sunlight, but what these reflections represent and the nature of their composition is still unknown.
“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 noted.
Dawn is an international science mission run by NASA and equipped with a trio of science instruments from the U.S., Germany, and Italy.
The visible and infrared mapping spectrometer (VIR), provided by Italy, is an imaging spectrometer that examines Ceres in visible and infrared light.
The team is using it to determine the temperatures of Ceres surface features, says Federico Tosi, investigator from the VIR instrument team at the Institute for Space Astrophysics and Planetology, and the Italian National Institute for Astrophysics, Rome.
Curiously, the various bright regions on Ceres appear to exhibit different temperature profiles, deepening their mysterious nature. Some spots, including the bright pair, have temperatures similar to their surroundings. Whereas others are cooler by comparison.
Dawn was launched on Sept. 27, 2007, by a United Launch Alliance (ULA) Delta II Heavy rocket from Space Launch Complex-17B (SLC-17B) at Cape Canaveral Air Force Station, Fla.
Stay tuned here for continuing updates on Dawns’ orbital capture and science mission at protoplanet Ceres!
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