A quantitative analysis of plume gas distributions from different detection studies on Europa

Abstract: The search for water has been vital in our solar system as water indicates a potential for life. The search has been extended to satellites orbiting the outer planets. It has already been proven that water exists on Saturn’s moon, Enceladus, where the spacecraft Cassini did a flyby through a water plume. The study of the water plumes has been implemented on Jupiter’s moon, Europa, where there are signs of an underwater ocean existing. Several studies have implemented an analytical model for the gas distribution of plumes to match the detected signals with their method of plotting the distribution of water gas. In this report, we quantitatively analyzed plume distributions used in studies by Roth et al. (2014), Blöcker et al. (2016), Sparks et al. (2016), Jia et al. (2019), Arnold et al. (2019), and Huybrighs et al. (2020). In these plume studies there are 2 different plume shapes used, namely the expanding teardrop and the expanding circular shape. Different scale heights are used for the teardrop shape, leading to either shorter or longer appearance of the teardrop plume. Comparing the plume distribution of these analytical plumes, Roth’s method is the most sensitive one in this category, meaning that Roth’s plume model had the lowest quantity in terms of the density distribution values. Arnold’s plume model is the densest for altitudes below roughly 300km and Huybrigh’s plume model for altitudes above 300km. In terms of the vertical and the horizontal column densities and the total number of molecules, the most sensitive method in each category was Jia’s, Roth’s, and Blöcker’s plume model respectively. Our results suggest that the plume models are rather inconsistent with each other quantitatively.