Simulated recovery of Europa's global shape and tidal Love numbers from altimetry and radio tracking during a dedicated flyby tour

Abstract

The fundamental scientific objectives for future spacecraft exploration of Jupiter's moon Europa include confirmation of the existence of subsurface ocean beneath the surface ice shell and constraints on the physical properties of the ocean. Here we conduct a comprehensive simulation of a multiple-flyby mission. We demonstrate that radio tracking data can provide an estimate of the gravitational tidal Love number k2 with sufficient precision to confirm the presence of a liquid layer. We further show that a capable long-range laser altimeter can improve determination of the spacecraft position, improve the k2 determination (<1% error), and enable the estimation of the planetary shape and Love number h2 (3-4% error), which is directly related to the amplitude of the surface tidal deformation. These measurements, in addition to the global shape accurately constrained by the long altimetric profiles, can yield further constraints on the interior structure of Europa. Key Points A multiple-flyby mission to Europa can recover key geophysical parameters Laser altimetry can uniquely and accurately recover the global shape of Europa Laser altimetry enables the recovery of h2 to constrain the ice shell thickness