Planetary Formation and Composition Studies

Planetary formation and composition studies investigate the processes that govern the birth, growth and internal structure of planets and smaller bodies within a protoplanetary disk. Dust grains and gas coalesce through accretion into kilometre-scale planetesimals, which further collide and merge to form planetary embryos and mature worlds. Collisional heating and radioactive decay drive differentiation, segregating metal-rich cores from silicate mantles and crusts. Volatile delivery and loss during impacts and aqueous alteration shape the distribution of water and light elements, while isotopic anomalies in meteorites and returned samples trace origins and mixing in the early Solar System. Advanced high-pressure experiments, numerical simulations and in situ analyses combine to elucidate material properties under extreme conditions, informing models of core formation, mantle convection and surface evolution. These insights have global significance for understanding Earth’s unique habitability, the diversity of exoplanets and the resources available for future space exploration.

Research from Nature Portfolio

Recent studies have demonstrated that under inner-core pressures and temperatures, hydrogen adopts a superionic state within hexagonal close-packed iron, diffusing anisotropically and aligning crystal axes in response to geomagnetic fields, thereby accounting for observed seismic anisotropy. Investigations of lunar crustal rocks using zinc isotopes reveal a two-stage volatile loss during Moon formation: an early depletion in the proto-lunar disk followed by magma-ocean degassing, suggesting the persistence of isolated volatile-rich domains. Advances in high-pressure thermodynamics have refined the equations of state for solid and liquid iron up to 350 GPa and 6000 K, delivering precise density and elastic parameters that serve as benchmarks for modelling planetary cores and reconciling seismic observations.

Planetary Formation and Composition Studies publication trend

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

Technical terms

Protoplanetary disk: A rotating circumstellar disc of gas and dust from which planets form.

Accretion: The gradual gathering of particles and bodies under gravity or electrostatic forces to build larger structures.

Planetesimal: A solid object, typically kilometre-scale, that represents an intermediate stage between dust grains and planetary embryos.

Isotopic anomaly: A deviation in the relative abundance of isotopes from a standard value, indicating distinct formation reservoirs or processes.

Superionic state: A phase in which one component (e.g. hydrogen) becomes highly mobile within a solid lattice.

Giant impact: A high-energy collision between large planetary bodies that can drive differentiation and alter composition.

References

1. Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field. Nature Communications (2023).
2. Extensive volatile loss during formation and differentiation of the Moon. Nature Communications (2015).
3. Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K. Scientific Reports (2017).
4. Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample. Science Advances (2023).
5. Origin of Isotopic Diversity among Carbonaceous Chondrites. The Astrophysical Journal Letters (2023).
6. The Role of Giant Impacts in Planet Formation. Annual Review of Earth and Planetary Sciences (2023).