- 1Tohoku University, Sendai, Japan (tomoki.nakamura.a8@tohoku.ac.jp)
- 2RDD/JAXA, Sagamihara, Japan
- 3ISAS/JAXA, Sagamihara, Japan
- 4Hokkaido University, Sapporo, Japan
The goal of the MMX mission is to determine the origin and the formation process of the two Martian moons (Kuramoto et al. 2022). Three years remote sensing observation of Phobos and Deimos (Nakamura et al .2021) will provide us mineralogical and compositional signatures of whole sphere of the moons and thus we will obtain strong constraints on the origin. Subsequent laboratory analysis of the returned samples from Phobos will terminate the long-standing problem of the origin of Martian moons.
In some cases, we can determine the origin based on only remote sensing observation. If Phobos has a high abundance of hydrous minerals, a high hydrogen concentration, a chondritic global chemical composition, and a reflectance spectrum similar to hydrous carbonaceous meteorites, then Phobos is made of primitive C or D-type asteroidal material. In this case, Phobos could be a captured asteroid coming from beyond Mars, or if it was formed by an asteroid impacting Mars, the impact would have been weak to maintain chondiritic composition.
The important scientific data to determine the origin of Phobos and Deimos are: global and local elemental abundances of Phobos (Laurence et al. 2019) with enough precision to distinguish chondritic or non-chondritic composition (including Martian components or not), the high resolution map of visible and near-infrared reflectance spectrra to explore the presence or absence of hydrated silicates on Phobos and Deimos (Barucci et al. 2021), and chemical, mineralogical and isotope composition of the returned samples to determine to determine whether Phobos is primordial solar system material or high-temperature heated processed material (Fujiya et al. 2021). If we succeed the remote sensing observations and return sample analyses, the origin and formation process of the Martian moons will be clarified within a few years from the sample return to the Earth expected in 2031.
References :
Barucci M.A. et al. (2021) Earth, Plan. and Space, 73, 211.
Fujiya W. et al. (2021) Earth, Plan. and Space, 73, 1.
Kuramoto K. et al. (2022) Earth, Plan. and Space, 74, 12.
Lawrence et al. (2019) Earth Space Science, 6, 2605.
Nakamura et al. (2021) Earth, Plan. and Space, 73, 227.
How to cite: Nakamura, T., Ikeda, H., Takeo, Y., Usui, T., Kuramoto, K., Working team, M. O., and Board, S.: MMX mission update and long-term operation plan in the whole mission period, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-22, https://doi.org/10.5194/epsc-dps2025-22, 2025.
