The role of phyllosilicates in shaping the Galilean moons' density gradient
- 1Aix Marseille Université, Institut Origines, CNRS, CNES, LAM, Marseille, France (olivier.mousis@lam.fr)
- 2Department of Astronomy, Cornell University, Ithaca, NY, USA
- 3Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX USA
- 4Aix-Marseille Université, CNRS, Institut Origines, PIIM, Marseille, France
- 5Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109-8001, USA
A key feature among the Galilean satellites is their monotonic decrease in density, indicating an ice fraction that is zero in the innermost moon Io, and about half in the outer moons Ganymede and Callisto. So far, there is no formation scenario that explains this gradient while considering the moons grew in a water-depleted circumplanetary disk. Here, we investigate the possibility that the jovian circumplanetary disk was fueled with ice-free chondritic minerals, including phyllosilicates. To do so, we use a standard one-dimensional gas-starved accretion disk model derived from the literature [1, 2] coupled with gas and solids transport modules [3, 4] to investigate the evolution of vapors released by the dehydration of phyllosilicates. We show that the dehydration of such particles and the outward diffusion of the released water vapor allows condensation of significant amounts of ice in the formation region of Ganymede and Callisto in the Jovian circumplanetary disk. This mechanism naturally explains the presence of ice-rich moons around a water-depleted Jupiter.
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[4] Anderson, S.E., Mousis, O., Ronnet, T. 2021. Formation Conditions of Titan's and Enceladus's Building Blocks in Saturn's Circumplanetary Disk. The Planetary Science Journal 2. doi:10.3847/PSJ/abe0ba
How to cite: Mousis, O., Schneeberger, A., Lunine, J., Glein, C., Bouquet, A., Vance, S., and Vinogradoff, V.: The role of phyllosilicates in shaping the Galilean moons' density gradient, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-855, https://doi.org/10.5194/epsc2022-855, 2022.
