The Dawn mission was launched in 2007 with an unconventional ion engine that let it first orbit Vesta, the asteroid belts second largest object, for 14 months before venturing on to Ceres in 2012. No single mission had ever orbited two extraterrestrial worlds before.

Vesta is a dry body almost like the Moon, Dawn Principal Investigator Carol Raymond of JPL tells Astronomy. Ceres we knew was a very water-rich object that had retained volatiles from the time it had formed. The two were sitting there like plums. The low-hanging fruit.

Ceres started to tease its secrets to astronomers with Dawns first glimpses of the dwarf planet in early 2015. A pair of weird white spots stood out from afar, shining like cats eyes in the dark. More of these bright features became apparent on approach, and they ended up at the center of scientists efforts to understand Ceres.

Much of Ceres story was apparent within just a few of Dawn's arrival, but scientists still felt they had more to learn, so NASA extended Dawns mission for a second run. This let the spacecraft keep collecting data until 2018, when it finally ran out of fuel. This latest batch of research was collected during that extended phase.

And as Dawn gathered higher resolution images, it started to unravel intimate details of the worlds surface and its ancient history. Among other things, the spacecraft spotted a lone mountain that stretches some 21,000 feet (6,400 meters) above the surface, taller than Denali, North Americas tallest peak.

Ceres' white spots sit inside Occator Crater, which stretches across 57 miles (92 kilometers) of the world's northern hemisphere. Another place with a prominent bright spot is within smaller Haulani Crater, named for the Hawaiian goddess of plants. Its one of the dwarf planet's youngest features.

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Ceres: An ocean world in the asteroid belt - Astronomy Magazine