Ceres' mysterious mountain Ahuna Mons is seen in this mosaic of images from NASA's Dawn spacecraft. Dawn took these images from its low-altitude mapping orbit, 385 kilometers above the surface, in December 2015. The resolution of the component images is 35 meters per pixel. On its steepest side, this mountain is about 5 kilometers high. Its average overall height is 4 kilometers. These figures are slightly lower than what scientists estimated from Dawn's higher orbits because new data from lower orbit gave scientists a better sense of Ceres' topography. The diameter of the mountain is about 20 kilometers. Researchers do not know how the feature formed, but they believe that its formation is unrelated to the similar-sized impact crater that it sits next to.