Did the Dwarf Planet Ceres Once Host Life? Astronomers Suggest Chemical Energy Could Have Fueled Microbes Long Ago

Though no direct evidence of life has been found, models suggest Ceres had hot water shooting into its underground oceans billions of years ago, offering potentially hospitable conditions

Margherita Bassi | Daily Correspondent

September 9, 2025

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Ceres, the only dwarf planet in our inner solar system, is covered in ice and salt deposits. Its daytime temperatures range from a frigid minus 136 degrees to minus 28 degrees Fahrenheit.

“Looking at this barren, frozen, gray world, we might be [forgiven] for thinking it the last place likely to host life in our solar system,” Iain Todd writes for BBC Sky at Night Magazine. And yet, researchers now suggest Ceres might have once been habitable.

In a study published in August in the journal Science Advances, astronomers reveal a new piece in the puzzle of Ceres’ history: The dwarf planet might have one had long-lasting chemical energy that could have sustained microbial life. While there is no evidence that life—not even single-celled organisms—ever existed on the dwarf planet, the new findings suggest that if any organisms were there, they might have had “food” available.

Thanks to data collected by NASA’s Dawn mission, which reached Ceres in 2015 and ended in 2018, researchers had already figured out that the dwarf planet had an underground reservoir of salty water as well as organic material in the form of carbon molecules. These are two key ingredients for hosting some microbial life, with chemical energy being the third.

In the recent study, the team created models to simulate the internal temperature and composition of Ceres over time. The models indicated that around 2.5 billion years ago, radioactive decay in the then-young world’s rocky interior could have caused hot water with dissolved gases to push up through the rocks and into the underground ocean.

This process is similar to how hydrothermal vents work on our own planet. These unique environments are marine regions where hot water shoots out of cracks in the ocean floor along with life-sustaining minerals, supporting entire ecosystems. Organisms known as chemoautotrophs can process chemical energy emitted by these hydrothermal vents.

“On Earth, when hot water from deep underground mixes with the ocean, the result is often a buffet for microbes—a feast of chemical energy,” Sam Courville, lead author of the study and a planetary geophysicist at Arizona State University, explains in a NASA statement. “So, it could have big implications if we could determine whether Ceres’ ocean had an influx of hydrothermal fluid in the past.”

According to the new models, Ceres is most likely to have been habitable between about 2.5 billion and 4 billion years ago, when its core’s temperature would have peaked and hot fluids would have reached the underground ocean. Since then, however, the dwarf planet’s ocean “has likely become a cold, concentrated brine with fewer sources of energy, making it less likely to be habitable at present,” the researchers write in the study.

In effect, the warmth from radioactive decay has weakened, much of the water has likely frozen and the remaining liquid is probably very salty. What’s more, Ceres isn’t heated by the gravitational push and pull caused by orbiting a large planet—the process that generates heat deep within Saturn’s moon Enceladus and Jupiter’s moon Europa, both possible candidates for hosting life.

The idea of potential past habitability might feel like a far cry from the long-awaited evidence that we’re not alone in the universe. However, Amanda Hendrix, director of the Planetary Science Institute who was not involved in the study, tells New Scientist’s Karmela Padavic-Callaghan that scientists need to investigate bodies like Ceres—worlds that have oceans now or had them in the past—if they hope to find clues to current or bygone life in our solar system.

Plus, the recent paper is relevant to the study of other water-rich, icy moons and dwarf planets that are about the size of Ceres. It suggests that even if these bodies don’t have internal heating right now, they might also have been hospitable long ago.

“If Ceres was habitable in the past, then probably there are tens of asteroids and moons that were also habitable in the past,” study co-author Joe O’Rourke, a planetary scientist at Arizona State University, tells New Scientist. “And if you can keep them hot, maybe [they are] still habitable today.”

Margherita Bassi | Read More

Margherita Bassi is a freelance journalist and trilingual storyteller. Her work has appeared in publications including BBC Travel, Discover magazine, Live Science, Atlas Obscura and Hidden Compass.