Ceres is the king of the asteroid belt, being the largest object in that region of the Solar System, and the Dawn spacecraft has shown it to be a very interesting world. While it is relatively small, classified as a dwarf planet, and very cold being so far from the Sun, there are hints that it has been surprisingly geologically active in the past and perhaps still is. Superficially it resembles the Moon or Mercury, gray and covered in craters. But there are also canyons, hazes, and unusual bright spots. Those spots have become a focus of much interest for scientists, and now new studies indicate that they appear to change in brightness from day to night, and may be evidence of ongoing activity inside Ceres.
It has been a year now since the Dawn spacecraft first reached the dwarf planet Ceres in the main asteroid belt between Mars and Jupiter, and during that time has shown Ceres to be a unique and complex little world. At first glance, Ceres just seems to be a heavily battered place, covered in craters like the Moon or Mercury, but a closer look reveals something more interesting: a small rocky world with large fractures, unusual “bright spots” randomly dispersed across the surface and an odd conical “mountain” which sits in isolation with nothing else like it around. Dawn has already acquired an enormous amount of data about Ceres, but now, in its lowest possible orbit, will continue to do for some time to come.
The Dawn spacecraft just recently entered its lowest and final orbit around the dwarf planet Ceres, providing the closest look ever at the puzzling world. Dawn will, of course, be taking thousands more high-resolution photographs, but what else will it be doing during the remainder of its mission? Various aspects of the mission will study Ceres in unprecedented detail.
There now might be a definitive answer to a puzzle which has intrigued both scientists and the public for some time: What are those odd bright spots on the dwarf planet Ceres? A new study suggests they are a type of salt, originating from a subsurface layer of briny water-ice. Another study points to the existence of ammonia-rich clays on Ceres.