Abstract Deimos, with a mean density of ∼1,480 kg m −3 similar to C‐type asteroids, may exhibit viscoelastic behavior due to its mixed ice‐rock interior. To efficiently simulate its tidal deformation, we approximate Martian tidal loading as a quasi‐static process using the average force between periapsis and apoapsis. Purely elastic displacement and stress fields are adopted as initial conditions for a Maxwell viscoelastic model, and long‐term evolution is simulated over 23.15 years. Key results under uniform density are: (a) the elastic energy evolves toward a quasi‐steady state while viscous dissipation remains finite throughout the simulation interval, indicating physically consistent energy behavior during long‐term Maxwell viscoelastic relaxation. (b) The displacement field follows the direction of tidal loading, confirming Mars' tidal force as the primary deformation driver. (c) The maximum displacement increases from 0.2 to ∼4 cm, indicating a weak Maxwell response. This suggests that Deimos' irregular shape is not shaped by current tides but is inherited from early‐stage processes. Its low deformation rate also implies substantial challenges for Phobos‐like tidal monitoring. (d) Despite the small displacement magnitude, both elastic and viscoelastic simulations reveal persistent stress localization within the interior and toward the southern concave surface. Von Mises stress fields exhibit nearly identical large‐scale spatial patterns in elastic and viscoelastic models, indicating that the dominant stress organization is primarily controlled by Deimos's irregular geometry and tidal‐loading configuration, rather than by rheological details. Therefore, the southern concave region represents a mechanically persistent stress‐concentration zone, rather than evidence for active failure under present‐day tidal conditions.
Zhong et al. (Sun,) studied this question.