NASA has released stunning new views of those mysterious bright spots on the dwarf planet Ceres – but we’re still not any closer to working out what they are.
The images were taken by the Dawn spacecraft from a height of 1,470 kilometers (915 miles) above the surface. The resolution in them is about three times better than previous images returned in June, with about 140 meters (450 feet) per pixel.
The bright spots on show here (although there are others on Ceres) are in the Occator crater, the rim of which is as high as 1.6 kilometers (1 mile) and is even vertical in some places. The spots are so bright that the only way to see them was to combine two images – one exposed correctly for the surface, and one correctly for the spots themselves.
"Dawn has transformed what was so recently a few bright dots into a complex and beautiful, gleaming landscape," said Marc Rayman, Dawn's chief engineer and mission director based at NASA's Jet Propulsion Laboratory in Pasadena, California in a statement. "Soon, the scientific analysis will reveal the geological and chemical nature of this mysterious and mesmerizing extraterrestrial scenery."
Theories for the identity of the bright spots are numbered, but the two favored at the moment suggest they are either ice or salt flats exposed on the surface, possibly by an impact. As Dawn spirals closer and closer in the coming months, the images will get better and better, with an answer possibly on the horizon.
In its current orbit, Dawn is due to map the entirety of Ceres six times over two months. Imaging the dwarf planet at different angles also allows scientists to create 3D maps of the surface. The video below shows an animation created using this technique, revealing the topography of the Occator crater.
But for now, the mystery of what formed the bright spots remains.