This image of dwarf planet Ceres, taken by NASA's Dawn spacecraft on June 15, 2015, shows a cluster of mysterious spots that are clearly brighter than their surroundings. Dawn took this image at an altitude of 2,700 miles (4,400 kilometers). The resolution is 1,400 feet (410 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19584