Ceres, a dwarf planet in the asteroid belt, may be an ocean world—at least in the sense that the apparently rocky surface may hide massive quantities of brine. Water is now thought by some scientists to be common in the solar system, and conditions on the 250-mile wide world invite suspicions it will be found there in abundance.
After five years studying a series of strange surface features around recently-formed craters, astronomers believe they're seeing signs of a large, subsurface body of briny liquid. Variations in Ceres' gravitational field back that up, implying that the underground reservoir of salty water may stretch horizontally beneath the ice for hundreds of miles and reach depths of roughly 25 miles (40 kilometers).
"Past research revealed that Ceres had a global ocean, an ocean that would have no reason to exist [still] and should have been frozen by now," study co-author and Dawn team member Maria Cristina De Sanctis of the National Institute of Astrophysics in Rome tells Astronomy. "These latest discoveries have shown that part of this ocean could have survived and be present below the surface."
If future missions can confirm the results, it will mean that there's a very salty, very muddy body of liquid somewhere around the size of Utah's Great Salt Lake on a dwarf planet that's just 590 miles (950 km) across — roughly the size of Texas.
Water was already known to be there thanks to the spectacular images taken by the Dawn explorer. Here are the authors of The Expanse in 2019, by then already lamenting their dry depiction of Ceres, addressing it to Dawn itself:
In 2011, we came out with a science-fiction novel called Leviathan Wakes that featured a big plotline on the dwarf planet Ceres, the largest object in the asteroid belt. In particular, we imagined a hard, nickel-iron Ceres with a population of millions thirsty for water harvested from the rings of Saturn. We did pretty well with the story; it got a Hugo nomination, and the publisher bought some follow-ups.
Four years later, we were launching a television show based on the book, starring the embattled crew of an ice hauler trying to keep Ceres Station hydrated. That was 2015—the same time you became the first spacecraft to orbit a dwarf planet. And as we gathered in the writer's room and on set, what did you tell us? Ceres has water. Lots of it. Not only that, you found large deposits of sodium carbonate on Ceres's surface, which doesn't sound that impressive until you realize it's evidence of ice volcanoes. Seriously. Ice volcanoes.
3:55We were barely out the gate, and not only were we already dated, we were outshone.
Would you live there? Here's Ceres, compared to the Earth and Luna in a NASA image:
Previously: NASA's Dawn spacecraft captures clearest-ever image of "dwarf planet" Ceres
