NASA’s Dawn space probe has taken its most detailed images yet of mysterious bright spots on the surface of dwarf planet Ceres – but they are still unsure what is producing them.
However, the mission scientists are confident that their studies will reveal the make-up and nature of the brilliant patches before long.
The brightest spots were evident from the start of this year as Dawn began to see some detail from a distance on the largest object in the asteroid belt between Mars and Jupiter.
But as the probe, which had already spent 14 months circling another asteroid, Vesta, got closer to Ceres, the spots became ever more fascinating.
The most prominent are found in a crater that has been named Occator after the mythological assistant to Ceres, the Roman goddess of agriculture and fertility.
Dawn’s latest images of Occator crater were taken from an altitude of 1,470 km (915 miles) and have a resolution of 140 metres (450 ft) per pixel, showing the spots in unprecedented detail.
The crater itself is interesting to planetary scientists because it has steep walls nearly 2 km (a mile) high, and almost vertical in some places.
Marc Rayman, Dawn’s chief engineer and mission director, who is based at NASA’s Jet Propulsion Laboratory, in California, said: “Dawn has transformed what was so recently a few bright dots into a complex and beautiful, gleaming landscape. Soon, the scientific analysis will reveal the geological and chemical nature of this mysterious and mesmerizing extraterrestrial scenery.”
The spacecraft has already mapped Ceres’ surface over two 11-day cycles from its current altitude, and began the third on September 9. It will map the whole of the dwarf planet six times over the next two months. Each cycle consists of 14 orbits. By imaging Ceres at a slightly different angle in each mapping cycle, Dawn scientists will be able to assemble stereo views and construct 3D maps.