A new study led by researchers from the University of Oxford and partners reports that Enceladus—one of Saturn’s icy moons—loses heat from both its north and south poles. This discovery strengthens the case that its global subsurface ocean could remain liquid over long time‑scales, a key requirement for life. The findings were published in Science Advances.

Previously, scientists believed heat was escaping only from the moon’s south polar region, where water‑ice plumes erupt from fractures. However, thermal data from the Cassini mission show that the north polar region also exhibits higher‑than‑expected surface temperatures. According to the modelling, the ice shell there supports conductive heat flow of about 46 ± 4 milliwatts per square metre.

By combining data for both poles, the team estimated a global heat loss of around 54 gigawatts. Remarkably, this figure aligns closely with predictions of energy input from tidal heating—when Saturn’s gravity flexes the moon’s interior and generates heat. This balance suggests the ocean beneath Enceladus’ icy crust may remain in a stable state.

🌊 Implications for Habitability and Future Exploration

Liquid water, heat, and key chemical ingredients are all considered essential to support life, and Enceladus ticks these boxes. The discovery of sustained heat flow over time means its ocean may not be transient or short‑lived. Instead, it appears thermally stable, increasing the possibility it could support life.

The study also refined estimates for the thickness of the moon’s ice shell. At the north pole, ice is estimated at 20–23 km depth, with a global average of 25–28 km. These measurements will help plan future missions that aim to probe the hidden ocean via landers or submersibles.

Lead author Dr Georgina Miles (Southwest Research Institute and visiting scientist at Oxford) commented: “We were surprised by how active the north pole is. Understanding Enceladus’ global heat budget is crucial to assessing its potential for life.”

The findings reignite interest in exploring Enceladus and other “ocean worlds” in our solar system. While there is no proof of life yet, the sustained conditions increase the chances that life could emerge or persist. The next steps will involve missions that can directly sample the sub‑surface environment.