[P-PS09] Mars and martian moons

[PPS09-04] Aerodynamic heating of Martian moon precursors prior to gas-drag capture

*Ryo N Matsuoka¹, Kiyoshi Kuramoto^1,2 (1.Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, 2.Institute of Space and Astronautiacl Science, Japan Aerospace Exploration Agency)

Keywords:Martian moons, Asteroid, Capture theory

One proposed source of water on terrestrial planets is the delivery of icy or water-bearing planetesimals from beyond the snowline via gravitational scattering by Jupiter (e.g. Raymond et al. 2006, 2009; Walsh et al. 2011). The spectral similarity between the Martian moons and D-type asteroids (e.g., Rivkin et al. 2002), which supports the capture theory, seems consistent with this scenario. If this hypothesis is correct, MMX may provide physical evidence of such a water delivery process (e.g., Kuramoto 2024).

The gas-drag capture theory for the origin of the Martian moons (Hunten 1979; Sasaki 1990) proposes that Mars captured planetesimals from heliocentric orbit through the action of aerodynamic drag exerted by a primordial atmosphere, which was formed by trapping gas from the primordial solar nebula. This hypothesis naturally explains not only the spectral properties of the Martian moons but also their orbital characteristics through three-body dynamics, including the effects of solar gravity (Matsuoka & Kuramoto 2023, JpGU). Since this hypothesis assumes a primordial solar nebula environment, if the moon precursors underwent orbital evolution via scattering by Jupiter, the transition of these bodies into high-random-velocity orbits just after scattering would have resulted in significant aerodynamic heating.

In this study, we apply the aerodynamic heating model for planetesimal by Tanaka et al. (2013) to the model orbits of Martian moon precursors proposed by Matsuoka & Kuramoto (2023) and discuss the possible thermal history of Martian moon material within this scenario.