Orbital and Thermal Characterization of Target Asteroids for the Emirates Mission to the Asteroid Belt

Thermal stress arises within materials due to expansion or contraction caused by temperature variations. On airless planetary bodies, such stresses play a critical role in the breakdown of surface materials subjected to repeated heating and cooling cycles. Previous analytical studies have shown that thermal stress amplitude and phase lag are influenced by an object's spin rate, size, thermal inertia, and material properties, particularly in the context of S-type asteroids. Ravaji et al. (2019) developed a one-dimensional heat diffusion and thermal stress model to evaluate subsurface temperature and stress profiles for rocks of varying sizes. Building on this framework, the present study extends the analysis by incorporating parameters such as rotation period, heliocentric distance, albedo, thermal inertia, density, and thermal expansion coefficient to evaluate both macroscopic and microscopic thermal stresses in airless bodies.

This work focuses on quantifying the magnitude and phase of thermal stress, along with the temperature profiles from the surface to subsurface layers, for the seven target asteroids of the Emirates Mission to the Asteroid Belt (EMA): 10253 Westerwald, 623 Chimaera, 13294 Rockox, 88055, 23871, 59980, and 269 Justitia (Parker et al., 2024). In addition to thermal characterization, the study also aims to perform dynamic characterization and potential family classification using Hierarchical Clustering Methods, as well as trajectory simulations based on data from the JPL Horizons ephemeris service and the Minor Planet Center database. 

Acknowledgments: The authors would like to acknowledge support by National Space Science and Technology Center (NSSTC), UAE University.

References:

[1] Parker, J. S., Al Hameli, F. S., Knittel, J., Pilinski, E., Baskar, S., Imler, P., & Almashjari, M. H. Proximity operations strategy for the Emirates mission to explore the asteroid belt (EMA).

[2] Ravaji, B., Alí‐Lagoa, V., Delbo, M., & Wilkerson, J. W. (2019). Unraveling the mechanics of thermal stress weathering: Rate‐effects, size‐effects, and scaling laws. Journal of Geophysical Research: Planets, 124(12), 3304-3328.