Ocean world and terrestrial planet

Earth

Earth is the benchmark for comparative planetology: liquid water, plate tectonics, life, and a coupled climate system.

Earth: loading local 3D asset.

Physics Snapshot

Planet order
3 from the Sun
Planet class
Inner terrestrial planet
Mean distance
1.0 AU
Revolution period
365.256 Earth days
Rotation period
23 h 56 m 4 s
Relative rotation speed
15.041 deg/s display
Mean temperature
15 C mean surface temperature
Atmosphere
Thick, life-modified nitrogen-oxygen atmosphere with active weather and climate cycles.
Main gases
About 78% nitrogen, 21% oxygen, 0.93% argon, plus carbon dioxide, water vapor, and trace gases.
Surface / cloud pressure
1.013 bar mean sea-level pressure.
Ocean status
Global liquid-water ocean covers about 71% of the surface; ice sheets, groundwater, lakes, and rivers complete the hydrosphere.
Perihelion / closest
0.98327 AU (147.09 million km)
Aphelion / farthest
1.01671 AU (152.10 million km)
Orbit ellipse
0.0167086
Mean/reference radius
6,371.0 km
Gravity definition
9.81 m/s²
Escape velocity
11.186 km/s
Day length
24 h
Known moons
1
Mission record
Earth-observing fleets include Landsat, Sentinel, Terra/Aqua, ICESat-2, SWOT, and many national systems.

What Scientists Watch

Classification: Inner terrestrial planet. Mercury through Mars are inner rocky worlds; Jupiter through Neptune are outer giants.

  • The magnetosphere and atmosphere reduce direct solar-wind exposure at the surface.
  • Earth observation satellites turn the planet into a continuously measured physical system.
  • The Moon stabilizes Earth's axial tilt over geologic timescales.

Exploration note: Earth-observing fleets include Landsat, Sentinel, Terra/Aqua, ICESat-2, SWOT, and many national systems.

Atmosphere and oceans

Gases, temperature, and liquids

Atmosphere
Thick, life-modified nitrogen-oxygen atmosphere with active weather and climate cycles.
Main gases
About 78% nitrogen, 21% oxygen, 0.93% argon, plus carbon dioxide, water vapor, and trace gases.
Pressure
1.013 bar mean sea-level pressure.
Surface / cloud temperature
About 15 C global mean surface temperature, with large regional and seasonal variation.
Oceans and liquids
Global liquid-water ocean covers about 71% of the surface; ice sheets, groundwater, lakes, and rivers complete the hydrosphere.
Stable surface liquids
Liquid water is stable across much of the surface.

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

Earth: loading local 3D asset.

This viewer loads the local asset-backed model for Earth 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 elevation framework spans the Himalaya, Andes, East African Rift, global mid-ocean ridges, abyssal plains, and deep trenches.
  • Plate tectonics continually recycles crust, so preserved impact craters are fewer than on comparably old airless bodies.
  • Topography, climate, erosion, and the water cycle are dynamically coupled in a way unique among the major planets.

Interior and field

Core, mantle, and magnetism

Crust
Oceanic and continental crust shaped by tectonics, volcanism, weathering, and sedimentation
Mantle
Convecting silicate mantle that drives plate motions and plume volcanism
Outer core
Liquid iron-alloy shell generating the geodynamo
Inner core
Solid iron-rich center under extreme pressure

Orbital characteristics

Detailed orbit solution

Epoch
J2000
Perihelion
0.98327 AU (147.09 million km)
Aphelion
1.01671 AU (152.10 million km)
Semi-major axis
1.00000 AU (149.60 million km)
Eccentricity
0.0167086
Sidereal period
365.256 Earth days
Solar year
365.2422 mean solar days
Average orbital speed
29.78 km/s
Inclination
0 deg by ecliptic definition
Longitude of ascending node
Reference orbit of the ecliptic
Argument of perihelion
114.207 deg

Physical characteristics

Bulk properties and rotation

Mean radius
6,371.0 km
Flattening
1 / 298.257
Surface area
510.1 million km²
Volume
1.08321 trillion km³
Mass
5.97217 × 10²⁴ kg
Mean density
5.514 g/cm³
Surface gravity
9.81 m/s²
Escape velocity
11.186 km/s
Sidereal rotation
23 h 56 m 4 s
Solar day
24 h
Equatorial rotation speed
465.1 m/s
Axial tilt
23.44 deg
Bond albedo
0.306

Atmosphere profile

Pressure, composition, and temperature

Surface pressure
1.013 bar
Composition
78.08% nitrogen, 20.95% oxygen, 0.93% argon, plus water vapor and trace gases
Surface temperature
About 15 C global mean
Hydrosphere
Liquid oceans cover about 71% of the surface

Field review

Magnetic field, core behavior, and crater context

  • Earth's dipole field forms a large magnetosphere that deflects most of the solar wind and shapes radiation-belt dynamics.
  • Secular variation, pole drift, and polarity reversals make the geodynamo an active area of planetary physics and paleomagnetism.
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Moon catalog

Moons Available

Confirmed count: 1

Moon.

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.

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