Occator crater is in the northern hemisphere of Ceres and is 57 miles (92 km) in diameter. The crater hosts a 7-mile-wide pit in the center, and its rim rises to 2,460 feet (750 meters) from the surface. Within the pit is a bright dome about 1.8 miles (2.9 km) across, which is made of the younger, bright material the MPS scientists found. Data from infrared cameras shows that it contains salts called carbonates.
One thing that makes researchers think the dome is cryovolcanic, rather than just something buried beneath the crater site, is that other, later impacts did not expose similar material.
To estimate the age of the crater and the dome, the team counted craters in the area. Lots of cratering means a given patch of surface is older and has been exposed longer.
The odds are that the impact that made Occator allowed the brine to come closer to the surface, eventually erupting out.
The new work was detailed Feb. 17 in The Astronomical Journal.
Follow Jesse Emspak on Twitter @Mad_Science_Guy. Original story on Space.com.