Motion on the surface of Titan: A multifaceted kinematics revealed in measurements by Huygens probe

In this work, we present and discuss the kinematics of a smooth metal sphere which is moving under the gravitational field of Saturn’s largest moon Titan, which has a denser atmosphere than the Earth mainly composed of nitrogen and methane. By using the numerical data regarding density and temperature in the Titan’s atmosphere provided by Huygens probe, high-altitude free fall with various initial heights and projectile motions with various initial speeds are considered with a drag force that is quadratic in speed. Equations of motion with two-dimensional quadratic drag, which constitute first-order nonlinear differential equations, were solved numerically. Strong speed dependency of the drag coefficient and the turbulent behavior at high Reynolds numbers emerge as complicated kinematics in the Titan’s atmosphere. Projectile trajectories as well as dynamic and energetic properties of the motion have been produced and discussed. The results can illuminate the nonlinear mechanics of the objects moving at the speeds that correspond to high Reynolds number in resistive media.