Numerical Simulations of Tidal Deformation and Resulting Light Curves of Small Bodies: Material Constraints of 99942 Apophis and 1I/‘Oumuamua

In this paper, we present an open source software ($\texttt{SAMUS}$) which simulates constant-density, constant-viscosity liquid bodies subject to tidal forces for a range of assumed viscosites and sizes. This solves the Navier-Stokes equations on finite-element mesh, incorporating centrifugal, Coriolis, self-gravitational, forces. The primary functionality is simulate deformation minor under influence It may therefore be used constrain composition physical structure experiencing significant forces, such as 99942 Apophis 1I/`Oumuamua. We demonstrate that $\texttt{SAMUS}$ will useful material properties during its near-Earth flyby in 2029. Depending properties, experience area change up 0.5\%, with similar effects photometric brightness. also apply dynamic viscosity 1I/`Oumuamua, first interstellar object discovered traversing inner Solar System. `Oumuamua experienced close approach Sun at perihelion ($q\simeq 0.25$ au) there were have caused body. could lead observable changes light curve based properties. application produce synthetic observations incorporate no -- infinite best reproduces data. While these results indicate did not deformation, sophisticated model non-principal axis rotation necessary conclusively analyze both Apophis.