While there is no conclusive evidence of microorganisms on Ceres, recent research bolsters the theory that this dwarf planet may have once harbored conditions conducive to single-cell life.
An illustration of Ceres’ interior, highlighting the movement of water and gas from the rocky core to the saltwater reservoir. Carbon dioxide and methane are chemical energy carriers beneath Ceres’ surface. Image credit: NASA/JPL-Caltech.
Previous scientific data from NASA’s Dawn Mission indicated that bright reflective areas on Ceres’ surface were formed from salt left behind by liquid that seeped from below ground.
A subsequent 2020 analysis identified that this liquid originated from a vast reservoir of subsurface brine.
Additional studies found organic materials in the form of carbon molecules on Ceres. While this alone doesn’t confirm the existence of microbial life, it is a crucial component.
Water and carbon molecules are two fundamental aspects of the habitability puzzle for this distant world.
The latest findings suggest that ancient chemical energy on Ceres could have supported the survival of microorganisms.
This does not imply that Ceres currently hosts life, but if it did, “food” sources are likely to have been available.
In a new study led by Dr. Sam Courville from Arizona State University and NASA’s Jet Propulsion Laboratory, a thermal and chemical model was developed to simulate the temperature and composition within Ceres over time.
They discovered that approximately 2.5 billion years ago, Ceres’ underground oceans possibly maintained a stable supply of warm water with dissolved gases emanating from metamorphic rocks in the rocky core.
The heat originated from the decay of radioactive elements within the planet’s rocky interior, a process typical in our solar system.
“On Earth, when hot water from deep underground interacts with ocean water, it frequently creates a fertility hotspot for microorganisms, releasing a wealth of chemical energy,” stated Dr. Courville.
“Therefore, if Ceres’ oceans experienced hydrothermal activity in the past, it would align well with our findings.”
As it stands, Ceres is not likely to be habitable today, being cooler and having less ice and water than it once did.
At present, the heat from radioactive decay in Ceres is inadequate to prevent water from freezing, resulting in highly concentrated saltwater.
The timeframe during which Ceres was likely habitable ranges from 5 billion to 2 billion years ago, coinciding with when its rocky core peaked in temperature.
This is when warm liquid water would have been introduced into Ceres’ groundwater.
Dwarf planets generally lack the benefit of ongoing internal heating due to tidal interactions with larger planets, unlike Enceladus and Europa, moons of Saturn and Jupiter, respectively.
Thus, the highest potential for a habitable Ceres existed in its past.
“Since then, Ceres’ oceans are likely to be cold, concentrated saltwater with minimal energy sources, making current habitability unlikely,” the authors concluded.
A paper detailing these findings was published today in the journal Advances in Science.
____
Samuel W. Courville et al. 2025. Core metamorphosis controls the dynamic habitability of the medium-sized marine world – the case of Ceres. Advances in Science 11 (34); doi: 10.1126/sciadv.adt3283
Source: www.sci.news
