A new study led by researchers from the University of Oxford, the Southwest Research Institute, and the Planetary Science Institute in Tucson, Arizona has revealed the first evidence of substantial heat flow from Enceladus’ north pole. This discovery overturns the long-held assumption that significant heat loss occurs only at the moon’s geologically active south pole. The finding confirms that Enceladus emits far more heat than expected for a passive icy body, reinforcing its status as a prime candidate for extraterrestrial life.

Enceladus is an unusually dynamic moon, known to possess a global, salty subsurface ocean that is thought to be the primary source of its internal heat. The combination of liquid water, heat, and essential chemical ingredients – such as phosphorus and complex hydrocarbons – makes this hidden ocean one of the most promising environments in the solar system for life beyond Earth. However, habitability depends on long-term stability. This balance is maintained through tidal heating, generated as Saturn’s gravity repeatedly stretches and compresses the moon during its orbit. Too little energy would allow the ocean to freeze, while too much could destabilize its internal environment.

Previously, direct measurements of Enceladus’ heat loss were limited to the south pole, where spectacular plumes of water vapor and ice erupt from surface fractures. The north pole, by contrast, was believed to be inactive. Using data from NASA’s Cassini spacecraft, the research team analyzed observations of the north polar region during deep winter in 2005 and summer in 2015. They measured how heat travels from the relatively warm subsurface ocean through the icy shell to the extremely cold surface, where it is radiated into space.

When combined with previously estimated heat loss from the south pole, Enceladus’ total heat output rises to about 54 gigawatts, closely matching theoretical predictions of tidal heating. This balance suggests the subsurface ocean could remain liquid for geological timescales, providing a stable environment where life might arise. The study also offers new estimates of ice shell thickness, valuable for future missions aiming to explore Enceladus’ ocean.

For more details, read the full article by University of Oxford.