Jens Asbjørn Bøgen
This surprising discovery suggests the icy world has the long-term thermal balance needed for life to possibly take hold.
A research team from Oxford University, the Southwest Research Institute, and the Planetary Science Institute has detected the first evidence of substantial heat flow at Enceladus’ north pole.
The study, published November 7 in Science Advances, suggests that the Saturn moon maintains a delicate thermal balance capable of keeping its subsurface ocean liquid for eons.
Until now, scientists believed that only the south pole — famous for its geysers that shoot vapor and ice into space — was geologically active.
The new measurements suggest Enceladus produces and releases far more energy than a frozen, inert world could.
This hints that its interior remains warm and dynamic, sustained by ongoing processes that could nurture life.
‘“Enceladus is a key target in the search for life outside the Earth, and understanding the long-term availability of its energy is key to determining whether it can support life,” said Dr. Georgina Miles of the Southwest Research Institute and Oxford University, who led the study, in a statement.
Ocean beneath the ice
Beneath Enceladus’ frozen crust lies a global ocean rich in salts and organic molecules.
Scientists believe this ocean is the source of the moon’s internal heat, produced as Saturn’s gravitational forces stretch and squeeze its core in a process known as tidal heating.
For life to exist, that ocean must stay liquid and stable over millions of years. Too little heat, and it would freeze; too much, and violent activity could disrupt any fragile biosphere that forms below the surface.
According to the researchers, the measured heat flow points to a near-perfect equilibrium between energy generation and loss — an essential condition for maintaining a long-lived ocean environment.
Measuring the polar heat
Cassini’s data gave scientists an unprecedented look at Enceladus’ north pole, previously thought to be dormant.
The team analyzed infrared readings captured during two key missions in 2005 and 2015 — one during the moon’s deep winter, the other during its summer.
By comparing expected temperatures with real infrared observations, scientists found the north pole was about 7 Kelvin warmer than models predicted.
The only plausible source of this extra heat, they say, is the warm ocean beneath the ice leaking energy upward.
The study estimates that the region emits 46 ± 4 milliwatts of heat per square meter — around two-thirds the energy escaping through Earth’s continental crust. Across the moon, that amounts to roughly 35 gigawatts, equivalent to the power output of tens of millions of solar panels.
Stable ocean world
When combined with heat from the active south pole, Enceladus’ total thermal emission reaches about 54 gigawatts — closely matching theoretical predictions from tidal heating models.
That near-perfect balance indicates that its internal ocean could remain liquid for vast periods, possibly long enough for life to evolve.
“Understanding how much heat Enceladus is losing on a global level is crucial to knowing whether it can support life,” said Dr. Carly Howett of Oxford University and the Planetary Science Institute. “It is really exciting that this new result supports Enceladus’ long-term sustainability, a crucial component for life to develop.”
Mapping for future missions
The findings also help refine estimates of the moon’s ice thickness — key information for designing future exploration missions. Data suggest the ice layer is around 20 to 23 kilometers thick at the north pole and roughly 25 to 28 kilometers thick elsewhere, slightly more than previous models indicated.
Dr. Miles noted that uncovering these subtle thermal patterns required years of patient analysis. “Eking out the subtle surface temperature variations caused by Enceladus’ conductive heat flow from its daily and seasonal temperature changes was a challenge, and was only made possible by Cassini’s extended missions,” she said.
She added that the research underscores the value of long-duration planetary missions, as “data might not reveal all its secrets until decades after it has been obtained.”
Sources: Science Advances, NASA, Oxford University, Southwest Research Institute, Planetary Science Institute, Science Daily
This article is made and published by Jens Asbjørn Bogen, who may have used AI in the preparation
