Compare the Sun and all eight planets side by side with scale-accurate sphere radii - click any world to highlight it and read published NASA mean-radius figures in the panel.
Play spin rotates the lineup slowly so limb curvature stays visible; pause freezes the view for screenshots. Earth starts highlighted with radius 6,371 km in the panel table.
Sphere radii follow published NASA mean radii - Sun 696,340 km, Jupiter 69,911 km, Saturn 58,232 km, Earth 6,371 km, Mercury 2,440 km - while row spacing is widened for readability. This is an educational size comparison, not an orbital model.
Planet Size Comparison 3D Explorer
Compare the Sun and all eight planets side by side with scale-accurate sphere radii - click any world to highlight it and read published NASA mean-radius figures in the panel.
Drag to orbit the view, scroll or pinch to zoom, and click Sun through Neptune to highlight a world while the camera nudges toward it. Toggle Play spin to rotate the lineup or pause for a still frame.
The facts panel lists Sun 696,340 km, Jupiter 69,911 km, Saturn 58,232 km, Earth 6,371 km, Venus 6,052 km, Mars 3,390 km, Uranus 25,362 km, Neptune 24,622 km, and Mercury 2,440 km - all NASA mean radii.
- Nine spheres in one row with radii proportional to published NASA mean radii
- Per-world highlight buttons from Sun through Neptune with camera nudge on select
- Play spin / Pause spin toggles slow group rotation for limb visibility
- Full comparison table in the facts panel with every mean radius in km
- Row spacing is widened for readability - orbital distances are not shown
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Teachers use it to show why Jupiter dwarfs Earth, students compare inner versus outer planet scale, and curious readers pause spin on Neptune to read 24,622 km beside Uranus at 25,362 km.
| World | Mean radius (km) | Source |
|---|---|---|
| Sun | 696,340 | NASA fact sheet |
| Jupiter | 69,911 | NASA fact sheet |
| Saturn | 58,232 | NASA fact sheet |
| Earth | 6,371 | NASA fact sheet |
| Mercury | 2,440 | NASA fact sheet |
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached; no scene data is sent to a server.
The scene is an educational size comparison tuned to teach planetary scale - it does not show heliocentric distances, orbital motion, or mass. Sphere radii are proportional; spacing between worlds is for readability only.
For a step-by-step walkthrough, read the Planet Size Comparison 3D Explorer step-by-step guide. The Space 3D collection also includes a Solar System 3D Explorer for orbiting planets with compressed sizes and a Moon Phases 3D Explorer for Sun-Earth-Moon phase geometry.
Frequently Asked Questions
What does Planet Size Comparison 3D Explorer show?
The Sun and all eight planets as spheres in one row with radii proportional to published NASA mean radii. Click any world button to highlight it, nudge the camera, and read its radius in km in the facts panel plus a full comparison table.
How is this different from Solar System 3D Explorer?
Solar System 3D Explorer shows planets orbiting the Sun with compressed sizes and distances so every orbit fits on one screen. Planet Size Comparison 3D Explorer keeps sphere radii scale-accurate side by side for a direct size lesson - spacing is widened for readability and there is no orbital motion.
What real figures does the panel include?
NASA mean radii in km: Sun 696,340; Jupiter 69,911; Saturn 58,232; Earth 6,371; Venus 6,052; Mars 3,390; Uranus 25,362; Neptune 24,622; Mercury 2,440. The table matches the spheres in the scene.
Are distances between planets shown to scale?
No. Only sphere radii are proportional to published mean radii. Row spacing is exaggerated so inner planets stay visible beside the Sun and Jupiter. For heliocentric distances and orbits, use Solar System 3D Explorer.
What does Play spin do?
Play spin rotates the entire lineup slowly so limb curvature stays visible on each sphere. Pause spin freezes the view for screenshots or classroom discussion while highlight buttons still work.
Is this an orbital or mass comparison?
No. The scene compares mean radius only - not mass, density, or orbital period. It is an educational visualization, not a planetary interior or gravity model.