James Webb Space Telescope Feed Post

Enceladus surface geometric albedo and detected water vapor emissions.

a) Surface geometric albedo of the trailing hemisphere normalized with respect to a reflected solar model. The spectrum shows several strong signatures of H2O ice, while no absorptions are observed at the expected wavelengths for CO2, CO or NH3 ice. b) Model of the observed water outgassing, in which 4 distinct regions are identified: the center region (orange circle) within 7 Enceladus radii (RE); the inner plume region between 7 and 30 RE; the extended plume region (blue contour)towards the South and between 30 and 38 RE; and the torus background region (pink contour)towards the North and between 30 and 38 RE. c) Data (black lines) and model (colored lines) of the H2O fluorescence emissions within the four regions of panel b, shifted vertically for clarity. The retrieved number of molecules for each region is also indicated. All models are consistent with a rotational temperature of 25 +=3K.