NASA/ESA/J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI)
Ceres was discovered in 1801, and originally classified as an asteroid. But it is much larger than its Asteroid Belt companions, so its status is now 'dwarf planet.'
Ceres was the first dwarf planet to receive a visit from a spacecraft with NASA's Dawn mission, which arrived at the strange world in 2015.
Nathues et al., Nature Astronomy
Five years later, the Dawn spacecraft has sent back high-resolution images of Ceres revealing new, exciting details. The images suggest the dwarf planet is an ocean world, with a deep reservoir of brine, or salt-enriched water.
Scientists believe the reservoir is linked to cryovolcanic eruptions, or related to a type of volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock, and is considered a phenomenon of the outer Solar System.
The data suggest cryovolcanism began just 9 million years ago on the dwarf planet. It was likely still active up until a million years ago, the data show — and may even be active today.
The latest discovery hints Ceres may be habitable. Its salt-water ocean could be rich in organic material.
Scientists will continue to pour over the data sent over by the Dawn spacecraft until a new mission heads for this unexpected ocean world — one to specifically explore its potential for life.