Dwarf planet Ceres, the largest known object in the asteroid belt and the lone dwarf planet in the inner solar system, is camouflaged by a layer of dust that disguises the true composition of its surface, findings of a new study suggest.
Data collected by NASA's Dawn spacecraft, which has been orbiting the extraterrestrial body for almost two years, and ground-based telescopes suggest that the surface of Ceres harbors water-bearing minerals such as clays and carbonates.
Observations made by NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), a modified Boeing 747 jet equipped with a 100-inch-wide telescope, however, hint that Ceres is not necessarily a carbon-rich body.
Ceres Coated By Material That Disguises Dwarf Planet's Real Makeup
Using data collected by SOFIA, astronomers detected a substantial amount of material on the surface of the dwarf planet that appears to be the debris of other asteroids. The "interplanetary dust particles" that often blaze up meteors when they collide with Earth's atmosphere are known to accumulate on the surface of smaller asteroids but it appears that they also build up on Ceres. The findings suggest that the body is coated by material that has partly disguised its real makeup.
Astronomer Franck Marchis, from the Search for Extraterrestrial Intelligence Institute, said that they found that the outer few microns of the dwarf planet's surface are partially cloaked with dry particles. The particles though do not come from Ceres itself but these are debris from asteroid impacts that may have happened millions of years ago.
"The most plausible scenario is that Ceres' surface has been partially contaminated by exogenous enstatite-rich material, possibly coming from the Beagle asteroid family," the researchers wrote in their study, which was published in the Astronomical Journal on Jan. 16.
Ceres Different From Neighboring C-type Asteroids
Ceres and 75 percent of all identified asteroids are in composition class "C" based on their similar colors. The new data gathered by SOFIA, however, revealed that Ceres is substantially different from neighboring C-type asteroids, which challenges conventional knowledge about the relationship of the dwarf planet and smaller asteroids. The findings also offered hints on the history of the dwarf planet.
"This scenario questions a similar origin for Ceres and the remaining C-types, and it possibly supports recent results obtained by the Dawn mission that Ceres may have formed in the very outer solar system," the researchers said.
Researchers likewise said that the findings shed light on questions about surface materials of asteroids accurately reflecting their intrinsic composition.
"Our results show that by extending observations to the mid-infrared, the asteroid's underlying composition remains identifiable despite contamination by as much as 20 percent of material from elsewhere," said Pierre Vernazza, from Laboratoire d'Astrophysique de Marseille.
Ceres May Shed Light On How Earth And Solar System Formed
Researchers are studying Ceres as it may provide information on the processes involved in the formation of planet Earth and the solar system. Last year, astronomers revealed that early in its history, the dwarf planet was a water world.