Bright spots on Ceres could be ice volcanos

Nature : Several bright spots have been observed on the asteroid Ceres by NASA’s Dawn spacecraft. The asteroid is known to have a significant amount of ice, but the way sunlight is being reflected indicates that the ice does not simply lie exposed on the asteroid’s surface. New images from Dawn have revealed that some of the bright spots located in craters are still visible even when the crater walls should block them from the Sun. That observation suggests that, if the reflections are due to ice, the ice must have been pushed up to significant heights. One explanation could be volcano-like eruptions of the ice caused by fluctuating internal pressures within the asteroid. Similar eruptions could also be caused by sunlight warming the asteroid’s surface as Ceres rotates from night to day, which could allow icy plumes to form that refreeze and then melt back down to the surface.