Martian Moons Formation and Exploration

The origins of Phobos and Deimos remain at the forefront of planetary science, with two principal scenarios under active debate: capture of primitive asteroids into Martian orbit and in situ formation from debris generated by a giant impact on early Mars. Their low densities, irregular shapes and surface regolith have inspired a range of theoretical and observational studies aimed at reconstructing their assembly and evolution. Orbital dynamics models explore how tidal interactions have driven Phobos inexorably inward and Deimos outward, while advanced covariance analyses of spacecraft trajectories promise refined maps of each moon’s gravity field. Remote-sensing campaigns across ultraviolet, visible, infrared, gamma-ray and neutron wavelengths are probing surface composition and mineralogy, revealing spectral affinities with carbonaceous chondrites and olivine-rich meteoritic analogues. Laboratory developments of spectral simulants support interpretation of surface reflectance, and moment-of-inertia modelling constrains internal layering and ice-rock proportions. The forthcoming Martian Moons eXploration (MMX) mission, scheduled for launch in 2024 with return of Phobos regolith in 2029, will integrate high-resolution imaging, in situ rover measurements and sample analysis to resolve formation mechanisms and to shed light on volatile delivery, planetary accretion processes and Mars-Moon system evolution.

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Martian Moons Formation and Exploration publication trend

The graph below shows the total number of articles in martian moons formation and exploration across all publications each year (not limited to Nature Index journals).

Technical terms

Rubble pile: A satellite composed of gravitationally bound aggregates of rock and dust with minimal internal cohesion.

Roche limit: The critical distance at which tidal forces from a primary body would disrupt a secondary body held together only by self-gravity.

Quasi-satellite orbit: A co-orbital configuration in which a spacecraft remains in the vicinity of a secondary body while both orbit a primary.

Libration amplitude: The angular range of oscillation a moon exhibits about synchronous rotation, used to infer internal mass distribution.

Spectral slope: The gradient of reflectance versus wavelength in a spectrum, indicative of surface composition and degree of space weathering.

References

1. Covariance analysis of periodic and quasi-periodic orbits around Phobos with applications to the Martian Moons eXploration mission. Astrodynamics (2023).
2. Exploring the Recycling Model of Phobos Formation: Rubble-pile Satellites* * Released on 2023 February 27.. The Astronomical Journal (2023).
3. Development of a new Phobos spectral simulant: spectral properties from visible to the mid-infrared range. Monthly Notices of the Royal Astronomical Society (2023).
4. The Mean Moment of Inertia for Irregularly Shaped Phobos and Its Application to the Constraint for the Two-Layer Interior Structure for the Martian Moon. Remote Sensing (2023).
5. Ultraviolet and Visible Reflectance Spectra of Phobos and Deimos as Measured by the ExoMars‐TGO/NOMAD‐UVIS Spectrometer. Journal of Geophysical Research Planets (2023).
6. Measuring the Elemental Composition of Phobos: The Mars‐moon Exploration with GAmma rays and NEutrons (MEGANE) Investigation for the Martian Moons eXploration (MMX) Mission. Earth and Space Science (2019).
7. Martian moons exploration MMX: sample return mission to Phobos elucidating formation processes of habitable planets. Earth, Planets and Space (2022).
8. Science operation plan of Phobos and Deimos from the MMX spacecraft. Earth, Planets and Space (2021).
9. The MMX rover: performing in situ surface investigations on Phobos. Earth, Planets and Space (2022).
10. The Importance of Phobos Sample Return for Understanding the Mars-Moon System. Space Science Reviews (2020).