Planetary Science

Planetary science unites studies of formation, evolution and present-day processes across the Solar System’s diverse bodies. It spans origin theories of protoplanetary discs, the accretion of planetesimals and the assembly of terrestrial and giant planets through collisions and migration. Once formed, planets develop layered interiors—cores, mantles and crusts—shaped by differentiation, convection and tectonism. The retention or loss of primordial volatiles gives rise to atmospheres whose composition, circulation and climate histories diverge widely, from runaway greenhouse on Venus to episodic glaciation on Mars and active weather on Earth. Magnetic dynamos or induced fields carve out magnetospheres that shield atmospheres and drive aurorae, while solar wind interactions sculpt plasma environments and control atmospheric escape. Surface processes—impact cratering, volcanism, erosion by wind, water or ice—record the interplay between internal heat, external forcing and planetary gravity. Comparative investigations, informed by remote sensing, in situ measurements and laboratory experiments, reveal universal principles and highlight the factors that make each world unique.

Research from Nature Portfolio

Global simulations reveal that transient southward turnings of the interplanetary magnetic field can drive large-scale convection in planetary magnetospheres solely via dayside reconnection. Modelled enhancements of field-aligned currents and two-cell patterns propagate from the bow shock to the nightside within tens of minutes, challenging the traditional view that tail reconnection is the sole driver of the circulation cycle.

Long-duration measurements by Cassini show that Saturn’s Bond albedo and internal heat flux are both higher than previously estimated, and that the planet’s global energy budget oscillates on seasonal timescales by more than ten per cent. These imbalances underpin episodic giant storms and hemispheric contrasts in cooling, with implications for the thermal evolution of icy and gas giants.

Far-infrared spectroscopy has yielded the first direct detection of ground-state atomic oxygen in Venus’s mesosphere, peaking around 100 km altitude on both day and night sides. This observation constrains photochemical production rates, maps the transition between zonal super-rotation and subsolar-to-antisolar flow, and provides a benchmark for models of cloud-top dynamics and trace-species loss.

Research from all publishers

New ab initio spectroscopic calculations show that collision-induced absorption by CO₂–H₂ and CO₂–CH₄ pairs can raise early Mars’s surface temperature above the freezing point under 1–2 bar CO₂ atmospheres with only a few per cent of added H₂ or CH₄. This mechanism resolves the faint-young-Sun paradox by linking transient reducing atmospheres to extended periods of liquid water stability.

Laboratory experiments demonstrate that simple collisions of millimetre-sized basaltic grains release gas-phase ions into the surrounding medium, implying that grain–grain impacts in protoplanetary discs can sustain ionisation levels previously thought absent in their midplanes. This process may enable MHD instabilities and drive chemical complexity in the earliest planet formation epochs.

A meta-analysis of turbulence tracers—including molecular line broadening, dust substructure lifetimes and disc evolution trends—indicates that turbulent motions in protoplanetary discs are weaker than classical viscous models predict but remain sufficient to mix material and contribute to angular-momentum transport. This finding supports scenarios where magnetised winds or hydrodynamic instabilities supplement or replace purely viscous accretion.

Planetary Science publication trend

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

Technical terms

Magnetosphere: The region around a planet dominated by its magnetic field, where charged particles are guided and trapped, forming boundaries such as bow shocks and current sheets.

Protoplanetary disc: A rotating circumstellar disc of gas and dust in which planets form by coagulation and accretion processes.

Collision-induced absorption (CIA): A mechanism whereby normally non-polar gas pairs temporarily absorb infrared radiation during binary collisions, enhancing greenhouse warming.

Bond albedo: The fraction of incident solar radiation reflected by a planet or moon over all wavelengths and angles.

Field-aligned current: An electric current flowing along magnetic field lines between a planet’s magnetosphere and ionosphere, driving auroral emissions.

Snow line: The radial distance in a protoplanetary disc beyond which temperatures are low enough for volatiles to condense into ices, affecting planet composition.

References

1. Global-scale magnetosphere convection driven by dayside magnetic reconnection. Nature Communications (2024).
2. Cassini spacecraft reveals global energy imbalance of Saturn. Nature Communications (2024).
3. Direct detection of atomic oxygen on the dayside and nightside of Venus. Nature Communications (2023).
4. Transient reducing greenhouse warming on early Mars. Geophysical Research Letters (2017).
5. Gas phase ions in protoplanetary discs from collisions of solids. Monthly Notices of the Royal Astronomical Society: Letters (2023).
6. Empirical constraints on turbulence in proto-planetary discs. New Astronomy Reviews (2023).