It was previously believed that heat not associated with solar radiation was found only at the south pole of Saturn’s moon Enceladus, where powerful geysers erupt from beneath the icy surface. However, it has now become clear that the internal heat of this small moon is distributed beneath the surface everywhere. This provides further evidence supporting the hypothesis of a global ocean beneath Enceladus’s icy crust.

Enceladus: A Promising Place to Search for Life

Astrobiologists consider Enceladus one of the most intriguing objects in the search for extraterrestrial life, even more promising than Mars. This moon, with a diameter of 504 kilometers, is located almost ten times farther from the Sun than Earth. At first glance, its frozen surface does not inspire much hope for the presence of life.

Geological Features and Surface Mysteries

After the Voyager 2 probe flew by in 1981, detailed images of Enceladus’s surface were obtained. These revealed vast plains with few impact craters, indicating the geological youth of these regions and the presence of processes that renew the surface. Additionally, Enceladus is located within Saturn’s dense E ring. There is a theory that this very moon creates the ring by ejecting water from its surface.

The Discovery of Geysers and Internal Heat

In 2005, the Cassini probe detected eruptions of steam and geysers near Enceladus’s south pole and also discovered abnormal surface warming. This points to the presence of an internal heat source within the moon. The main theory for the origin of this heat is tidal heating, caused by Saturn’s gravitational influence. As Enceladus moves along its slightly non-circular orbit, it deforms, generating internal friction and heat. As a result, fractures—known as “tiger stripes”—formed in the south, from which geysers erupt. In these areas, the crust is thinner and constantly cracks due to deformation.

A Global Ocean Beneath the Ice

Researchers believe that beneath Enceladus’s multi-kilometer-thick icy shell lies an ocean of liquid, likely very salty, water. Previously, internal heat was detected only in the south, which led to the theory of a large subsurface lake rather than a global ocean.

New Data: Heat Across the Entire Surface

Recently, American planetary scientists analyzed data from the Cassini probe’s infrared spectrometer, collected over the north pole of Enceladus in different years. In July 2005, the northern part of the moon was in complete darkness for about 10 Earth years and cooled to around minus 235 degrees Celsius, making it easy to detect internal heat.

The temperature in the north turned out to be about seven degrees higher than it would be without an internal heat source. This indicates that internal heat escapes from Enceladus across its entire surface, and the subsurface ocean extends beneath the entire crust. The crust’s thickness in the north ranges from 20 to 23 kilometers, while in the south, near the geysers, it does not exceed five kilometers.