Named after the Roman Goddess of the harvest, the icy dwarf planet Ceres has been found to be geologically active after close examination of NASA’s Dawn spacecraft’s final findings before its death. Ceres, despite being less than 1/3 of the size of our Moon, apparently has ice volcanoes and remnants of an ancient ocean, potentially even harbouring liquid water.
The craft’s findings suggest that Ceres has salty liquid water seeping out on its surface, as well as a diverse landscape of hills and mounds that formed when the ice melted as a result of an asteroid impact 20 million years ago, and subsequently refroze to form the landscape, while also leaving a 91 km-wide crater known as Occator on the surface. These findings also support the existence of something known as ‘cryovolcanoes’ on the dwarf planet, erupting with ice-cold salty mud or slush instead of the molten lava we are used to on Earth. Dawn even spotted hints of an eruption of brine within the past few decades.
“We’ve provided strong evidence that Ceres is geologically active in the present, [or] at least in the very recent past,” said Dawn’s principal investigator Carol Raymond, the manager of the NASA Jet Propulsion Laboratory’s Small Bodies Program in Pasadena, California. “And there’s some tantalizing evidence that it could be ongoing.” This also means that the dwarf planet has, at some point, had all the building blocks for organic life at some point: liquid water, energy and carbon-based organic molecules, theoretically making the planet inhabitable for at least some time after the asteroid collision.
The presence of brine pockets (as detected by Dawn) also seemingly point to the past existence of a planet-spanning ocean. This is possible despite the frigid temperatures, as dissolved salt can keep water in a liquid state even at sub-zero temperatures. Fortunately, Ceres is located relatively close to Earth, orbiting the Sun as part of the asteroid belt between Mars and Jupiter, making it an ideal target for future research.