Gas giant

Saturn

Saturn is a low-density giant with bright icy rings and moons that are laboratories for habitability and geology.

Saturn: loading local 3D asset.

Physics Snapshot

Planet order
6 from the Sun
Planet class
Outer gas giant
Mean distance
9.537 AU
Revolution period
10,759.22 Earth days
Rotation period
10.656 hours
Relative rotation speed
33.784 deg/s display
Mean temperature
-140 C mean cloud-top temperature
Atmosphere
Deep hydrogen-helium giant atmosphere with banded clouds, storms, and a low-density interior.
Main gases
Mostly hydrogen with helium, methane, ammonia, phosphine, water vapor, and other trace gases.
Surface / cloud pressure
No solid surface; 1-bar cloud-level values are used for comparison.
Ocean status
No planetary surface ocean. Enceladus has a subsurface ocean, and Titan has surface methane-ethane lakes and seas.
Perihelion / closest
9.0412 AU (1.353 billion km)
Aphelion / farthest
10.1238 AU (1.515 billion km)
Orbit ellipse
0.0565
Mean/reference radius
58,232 km
Gravity definition
10.44 m/s²
Escape velocity
35.5 km/s
Day length
10.7 hours
Known moons
285 confirmed
Mission record
Pioneer, Voyager, Cassini-Huygens, and the planned Dragonfly mission to Titan.

What Scientists Watch

Classification: Outer gas giant. Mercury through Mars are inner rocky worlds; Jupiter through Neptune are outer giants.

  • The rings are structured by resonances, embedded moonlets, and collisions.
  • Titan has a nitrogen atmosphere, methane weather, and organic chemistry.
  • Enceladus vents ocean material into space, allowing plume sampling concepts.

Exploration note: Pioneer, Voyager, Cassini-Huygens, and the planned Dragonfly mission to Titan.

Atmosphere and oceans

Gases, temperature, and liquids

Atmosphere
Deep hydrogen-helium giant atmosphere with banded clouds, storms, and a low-density interior.
Main gases
Mostly hydrogen with helium, methane, ammonia, phosphine, water vapor, and other trace gases.
Pressure
No solid surface; 1-bar cloud-level values are used for comparison.
Surface / cloud temperature
About -140 C near the 1-bar cloud level; warmer at depth.
Oceans and liquids
No planetary surface ocean. Enceladus has a subsurface ocean, and Titan has surface methane-ethane lakes and seas.
Stable surface liquids
No solid surface; interior hydrogen becomes dense fluid under pressure.

Interpretation note

How to read these values

Rocky worlds list surface conditions directly. Jupiter, Saturn, Uranus, and Neptune do not have hard surfaces, so temperature and pressure are referenced to atmospheric levels such as the 1-bar cloud region.

Ocean status separates the planet itself from its moons. Several outer-planet moons are major ocean-world targets even when the parent planet has no surface ocean.

3D asset view

Rotatable planet model

Saturn: loading local 3D asset.

This viewer loads the local asset-backed model for Saturn and applies the sidereal axis tilt and relative rotation direction for study. Drag to rotate, wheel to zoom, and open full screen for close inspection.

Elevation and relief

Topography map notes

  • The visible map is atmospheric: banded clouds, storm tracks, and the north-polar hexagon replace rock relief.
  • Ring topography matters dynamically, from dense B-ring structure to the Cassini Division and embedded moon resonances.
  • Seasonal illumination changes alter the observed brightness and contrast of both atmosphere and rings.

Interior and field

Core, mantle, and magnetism

Upper atmosphere
Ammonia and deeper water cloud systems above rapid zonal winds
Molecular hydrogen shell
Deep fluid envelope containing most of the visible planet
Metallic hydrogen region
Conducting deep layer linked to Saturn's dynamo
Core
Rock-ice heavy-element core under enormous pressure

Orbital characteristics

Detailed orbit solution

Epoch
J2000
Perihelion
9.0412 AU (1.353 billion km)
Aphelion
10.1238 AU (1.515 billion km)
Semi-major axis
9.5826 AU (1.434 billion km)
Eccentricity
0.0565
Sidereal period
10,759.22 Earth days
Synodic period
378.09 Earth days
Average orbital speed
9.68 km/s
Inclination
2.485 deg to the ecliptic
Longitude of ascending node
113.715 deg
Argument of perihelion
339.392 deg

Physical characteristics

Bulk properties and rotation

Mean radius
58,232 km
Flattening
0.09796
Surface area
42.7 billion km²
Volume
827.13 trillion km³
Mass
5.6834 × 10²⁶ kg
Mean density
0.687 g/cm³
Reference gravity
10.44 m/s²
Escape velocity
35.5 km/s
System III rotation
10 h 33 m 38 s
Equatorial rotation speed
About 9.87 km/s
Axial tilt
26.73 deg
Geometric albedo
0.499

Atmosphere profile

Pressure, composition, and temperature

Pressure reference
1-bar cloud level
Composition
Mostly hydrogen and helium with methane, ammonia, phosphine, and water vapor traces
Cloud-top temperature
About -140 C near the 1-bar level
Surface note
No hard surface; rings and atmosphere dominate the visible system

Field review

Magnetic field, core behavior, and crater context

  • Saturn's magnetic axis is unusually well aligned with its rotation axis, which makes the dynamo geometry especially interesting.
  • The magnetosphere couples to the rings and icy moons, especially Enceladus, which injects water products into the plasma environment.
No enduring cratered cloud-top surfaceNorth-polar hexagonGreat White Spot storm systemsRing gaps and density waves

Moon catalog

Moons Available

Confirmed count: 285 confirmed

Major and named examples: Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Iapetus, Phoebe, Janus, Epimetheus, Prometheus, Pandora, Atlas, Pan, Telesto, Calypso, Helene, Polydeuces, Methone, Pallene, Daphnis, Anthe, Aegaeon, plus many small irregular moons and recent provisional satellites S/2020 S 45-S/2020 S 48 and S/2023 S 51-S/2023 S 57.

Data note: rotation values are sidereal periods. For solar orbits this guide uses perihelion and aphelion; those are the Sun-orbit equivalents of closest and farthest orbital distance. Gravity is surface or equatorial gravity for rocky planets and a reference-level value for giant planets, so rounded fact sheets may differ slightly. Moon counts can change when new satellites are confirmed.

Data basis

How these values are normalized

Orbital elements are presented in a J2000-style reference format. Rotation values use sidereal periods unless a solar day is explicitly named. For giant planets, pressure, temperature, and gravity are reference-level values because there is no solid surface to stand on.

Audit note

How to read discrepancies

Compact summary boxes, environment notes, and detailed fact tables are now aligned to the same field guide data blocks. This consistency pass was updated on May 5, 2026. Small differences can still appear when a quantity is rounded for readability, when a rocky-planet surface value is contrasted with a giant-planet reference level, or when moon counts change after new confirmations.

Mathematical model

Planet rotation and scale model

Planet meshes are procedural study models: radius, axial tilt, and rotation come from catalog fields, while surface textures are visual aids. The mathematical model does not infer planet shape from a picture.

Rotation phase

\[\theta(t)=\theta_0+\frac{2\pi t}{P_{\mathrm{rot}}}\]

The displayed spin angle advances from the body's rotation period P_rot. Retrograde rotation is represented by the sign of P_rot.

Axial tilt

\[\mathbf{r}_{\mathrm{tilted}}=R_z(\varepsilon)\,\mathbf{r}_{\mathrm{body}}\]

The spin axis is tilted by an explicit obliquity epsilon. The proof is a rigid-body rotation matrix, not an artist-drawn axis.

Scale contract

\[R_{\mathrm{scene}}=k\,R_{\mathrm{catalog}}\]

Scene radius is a scalar multiple of catalog radius unless the user chooses a readability mode. The page states when visual radius is bounded so the model is not mistaken for exact visual scale.

Verification standard: the rendered object must be reproducible from stated equations, catalog parameters, or explicit geometric transforms. Visual reference images may inform presentation only; they are not the source of orbital positions, field vectors, accretion-disk gradients, timing, or engineering layout.

Limitations: browser scenes may use bounded scale, compressed distances, simplified two-body dynamics, schematic transfer curves, or educational approximations where full numerical ephemerides, CFD, finite-element models, or general-relativistic ray tracing are outside the page scope. Those simplifications are part of the model contract, not hidden image-based construction.

Open the full site-wide mathematical verification policy