A NASA spacecraft is closing in on the dwarf planet Ceres after a nearly eight-year journey.
Plans call for Dawn to slip into orbit around Ceres early Friday to begin a 16-month mission. Ceres is the largest object in the asteroid belt between Mars and Jupiter, which contains rocky remnants from the formation of the solar system some 4.5 billion years ago.
Scientists have puzzled over a pair of bright spots — possibly exposed ice or salt — visible in a crater on Ceres. They’ll get a better look once the mission is underway.
