Computing the Radiant Energy Budget of Enceladus



Journal Title

Journal ISSN

Volume Title



One of the most important findings from the 20-year (1997-2017) Cassini mission is the discovery of jet plumes on Enceladus (e.g., a small satellite of Saturn with a size ~ 500 km). These jet plumes (~ a few hundred kilometers in height) are driven by liquid water/water ice and have led Enceladus to become one of the best candidates in finding a place suitable for past or present life in our solar system. Here we seek to better understand the geological system of Enceladus by analyzing its radiant energy budget with Cassini's observations. The radiant energy budget, determined by the emitted thermal energy and absorbed solar energy, can be used to estimate the internal heat which plays a critical role in driving the jet plumes. The thermal spectra recorded by one infrared instrument (i.e., CIRS) aboard the Cassini spacecraft are used to measure the emitted thermal energy. Data from the visible and near-infrared instruments (i.e., ISS and VIMS) on Cassini are used to measure the absorbed solar energy. Based on the measurements of the emitted thermal energy and the absorbed solar energy, we can determine Enceladus' radiant energy budget and the related internal heat. We have achieved some promising results (e.g., the solar flux and the full-disk albedo of Enceladus at some wavelengths). We will finish the measurements of Enceladus' radiant energy budget, which will be used to improve models of Enceladus’ thermal structure and explain the incredible jet plumes.