Bright spots on Ceres remain a mystery
DOI: 10.1063/PT.5.029661
Guardian : Last year when NASA’s Dawn spacecraft arrived at Ceres—a dwarf planet located in the asteroid belt between Mars and Jupiter—it observed some 130 bright spots dotting the otherwise dark surface. Because the spots appeared to brighten during the day and grow dimmer at night, it had been proposed that they were caused by the presence of water vapor that emanated from a layer of ice trapped beneath the surface and warmed by the Sun’s rays. New data from the European Southern Observatory in Chile, however, show that whereas the spots brightened and dimmed in July, there was little change in August. According to Paolo Molaro of the Trieste Astronomical Observatory and colleagues, it is possible that “the cycle of evaporation and freezing could last more than one rotational period,” and so the system may be more complex than previously thought.
