A peculiar density profile inside Jupiter

le 6 décembre 2024, 10h45 à 12h45, Florian Debras, salle Jules Verne, OMP, site Belin

Resumé: Since 2016, the Juno satellite is orbiting Jupiter and has completely changed our understanding of the planet. From the atmosphere to the deep interior, including the auroras, Juno is providing a wealth of data that challenges models of Jupiter. Notably, the gravitational data are incompatible with previous interior models hence new, more complicated models have been put forward. One of the peculiarity of these models is the need, at a given pressure, for a density lower than the density of the external adiabatic profile of Jupiter, which seems unphysical at first glance. In this seminar, I will first explain how to invert the gravity data to derive internal structures of planets, and what this implies to the density profile of Jupiter. I will detail the essential connexion with the atmosphere and the evolution of the planet, and will then expand on the need for a « subadiabatic » density profile. Such profile is indeed justified physically, provided there is a change in the thermodynamics quantity of the matter inside giant planets. The possibility for this density profile in giant planets bears strong consequences on our understanding of the evolution of giant planets and exoplanets.