The spacecraft has been circling Ceres since 2015. In June, it reached its lowest orbit yet, skimming the surface from just 22 miles (35 kilometers) up.
The latest pictures released Monday offer unprecedented views of a huge impact crater known for its bright salty deposits. Landslides are clearly visible on the rim.
Chief engineer Marc Rayman of NASA's Jet Propulsion Laboratory in Pasadena, California, says the results are better than hoped.
Before arriving at Ceres, Dawn explored the asteroid Vesta. Both are in the asteroid belt between Mars and Jupiter.
Launched in 2007 with an ion engine, Dawn is nearing the end of its extended mission. NASA expects the spacecraft to last just another few months.