NASA's Cassini Mission Reveals Life-Promoting Conditions on Enceladus

New research from NASA's Cassini mission reveals significant heat flow from both poles of Enceladus, one of Saturn's moons, indicating conditions potentially favorable for life. This groundbreaking discovery was published on November 7 in Science Advances.

Scientists from Oxford University, the Southwest Research Institute, and the Planetary Science Institute have found evidence of unexpected heat release at Enceladus' north pole, contradicting previous beliefs that heat loss was limited to the south pole, where geysers expel water vapor and ice particles into space.

The presence of a global, salty ocean beneath the icy surface of Enceladus is the main source of this internal heat, essential for sustaining life. The ocean contains liquid water, warmth, and vital chemical ingredients, making it one of the most promising environments in the solar system for extraterrestrial life.

For life to thrive, it’s crucial that this ocean remains stable over long periods, maintaining a balance of energy gained and lost. Tidal heating from Saturn's powerful gravitational influence is responsible for this balance.

Dr. Georgina Miles, the study's lead author, emphasized the importance of understanding the long-term energy availability of Enceladus for assessing its potential to support life. The research team utilized data from the Cassini spacecraft to analyze the north pole during the deep winter of 2005 and the summer of 2015.

Their findings indicated that the north pole's surface was approximately seven Kelvin warmer than expected, attributed to heat escaping from the subsurface ocean. The measured heat flow was about 46 milliwatts per square meter, which translates to a total energy output of around 35 gigawatts across the moon.

This is equivalent to the power generated by 66 million solar panels or 10,500 wind turbines. When combined with previously detected heat at the south pole, Enceladus' total heat loss reaches approximately 54 gigawatts, aligning with predictions from tidal force models.

This balance suggests that Enceladus' ocean could remain liquid over long spans, thus providing a stable environment for life development. Understanding the longevity of this ocean is crucial, as it may have existed for billions of years, allowing stable conditions for potential life.

The research also provides insights into the thickness of Enceladus' ice shell, which is estimated to be between 20 to 28 kilometers thick. This information is vital for planning future missions that aim to explore the moon's ocean for signs of life.

Dr. Miles concluded by noting the importance of long-term missions to ocean worlds, stressing that the data obtained from Cassini may continue to reveal insights for years to come.