A world beneath our feet.

A real planet, an interpreted interior.

Earth’s mean radius is 6,371 km. The cutaway uses spherical layer proportions, with a 24.4 km reference crust, approximate mantle landmarks at 410 and 660 km, a core–mantle boundary at 2,891 km and an inner-core boundary at 5,149.5 km. Real boundaries vary geographically. The crust is particularly variable; the oceans and continents in the surface texture do not change this reference shell’s thickness. The inner core stays visible while the probe explores its centre.

Density follows the published polynomials in the Preliminary Reference Earth Model (PREM, 1981). Gravity uses the mass inside your radius, g = GM(r)/r²; the value at the centre is zero. Pressure is integrated inward from a zero-pressure surface using hydrostatic balance, dP/dr = −ρg, with sampling intervals no larger than 1 km and breaks at each PREM discontinuity. These are spherical, nonrotating reference calculations. Rotation, local geology, topography and regional anomalies are excluded. PREM includes a global-average ocean layer; it is not a specific location beneath the surface map. Its original transition steps are at 400 and 670 km, slightly different from the modern approximate 410 and 660 km visual landmarks.

The camera moves continuously through one reference cutaway. Local features are illustrative patterns anchored to its cut faces, not measured surveys beneath geographic locations. Relief, pore spaces, crystals, distances and motion are exaggerated or schematised. They cannot be used for hazard, drilling, groundwater or local-pressure predictions. Readouts continue to describe the global PREM reference at the example depth. Regional examples and their uncertainty are identified in each feature’s evidence notes. Mineral grains are not exact atomic lattices. Warm paths in the outer core represent illustrative liquid motion, not magnetic-field lines. The scene does not solve the geodynamo equations.

Temperature ranges are estimates, not measurements at the selected point or outputs of a heat-flow simulation. Deep-core temperatures and composition remain uncertain. Colours, mineral grains and fluid motion are illustrative and not to scale; visible motion is strongly time-compressed. Much of our knowledge comes from seismic waves, laboratory experiments and Earth’s mass and magnetic field.

Sources and credits

• PREM: the original reference Earth model ↗
• USGS: inside the Earth ↗
• British Geological Survey: Earth structure and seismic waves ↗
• McDonough (2024): Earth composition and geodynamics ↗
• USGS: introduction to geomagnetism ↗
• NASA: Earth’s mean radius ↗
• USGS: aquifers and groundwater (2026) ↗
• National Park Service: cave geology ↗
• USGS: Yellowstone reservoir research (2025) ↗
• USGS: investigating the Moho ↗
• USGS: Slab2 subduction geometry ↗
• Wolf and colleagues: plume-root research (2024) ↗
• JGR: global ULVZ study (2026) ↗
• Nature Communications: core crystal research (2025) ↗

Surface and cloud maps: Solar System Scope / INOVE, CC BY 4.0. Map credits and adaptations. Interior and rock textures are procedural illustrations. Research reviewed November 3, 2026.

Keyboard: Tab through the map labels and press Enter to explore. Arrow keys turn the camera around the part you are exploring. Use +/− to zoom. Escape returns to the Earth map when the view is not expanded. Measurements are optional. Reduced-motion preferences disable ambient material motion.