Table 1 MMX mission objectives corresponding to MSA observations

1.1

1.1.1

1

Reveal whether Phobos originated as a captured asteroid or resulted from a giant impact

Spectroscopically reveal the surface-layer distribution of the materials that make up Phobos with the spatial resolution required for the scientific evaluation of sampling points and geological structures, thereby constraining Phobos’ origin

Measure refractory ions (Si⁺, Ca⁺, Fe⁺, etc.) emitted from the Phobos surface

1.1.3

2

Obtain information such as molecular release rates and mass distribution related to the presence of ice in Phobos, investigate the presence or absence of density contrasts on Phobos’ surface, and constrain Phobos’ origin independently of MO1.1.1 and MO1.1.2

Measure water-related ions (O⁺, OH⁺, H₂O⁺, etc.) originating from inside Phobos (if they exist)

2.1

2.1.1

3

Obtain a basic description of the elementary processes of surface evolution for moons in the circum-Martian environment

Identify weathering and evolutionary processes (impact frequency, degree of gardening, and space weathering processes) in surface-layer regolith specific to the Martian moons as compared to asteroids

Measure incident ions to Phobos (H⁺ and He⁺⁺ of the solar wind and O⁺ and O₂⁺, etc. of the escaping ions from the Martian atmosphere), scattered ions, and emitted ions with monitoring the surrounding magnetic field

2.2

2.2.2

4

Add new findings and constraints on the history of changes in the Martian surface

Place constraints on the amount of atmospheric escape through the history of Mars from composition ratios and isotopic ratios in the current escaping atmosphere

Measure O⁺, C⁺, N⁺, Ar⁺, and their key isotopes in the escaping ions from the Martian atmosphere