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How to Explore the Mercury Spin-Orbit Resonance 3D Explorer
Open the Mercury Spin-Orbit Resonance 3D Explorer, scrub through a full 176-day solar day, and watch Mercury complete exactly 3 rotations for every 2 orbits while its two hot-pole markers swap which one faces the Sun at successive perihelion passes.
- Open https://freetoolonline.com/space-3d/mercury-spin-orbit-resonance.html and wait for the Sun, the eccentric orbit ellipse, and the Mercury sphere with its two hot-pole markers to render.
- Use the Object selector to pick the 3:2 resonance itself, Mercury's rotation, Mercury's orbit, or the Sun.
- Drag the Day-of-solar-day scrub slider (0-176) or click "Play Solar Day" to advance Mercury around its real-eccentricity orbit while it spins at its real rotation rate.
- Watch the two orange hot-pole markers swap which one leads toward the Sun between one perihelion pass (the red dot) and the next.
- Look at the facts panel for the selected view's real rotation period, orbital period, ratio, solar-day length, and eccentricity, plus a live count of rotations and orbits completed at the current day.
- Switch views and scrub again to compare how the numbers and the marker swap line up.
Key published figures
| Figure | Value |
|---|---|
| Sidereal rotation period | 58.646 Earth days |
| Sidereal orbital period | 87.969 Earth days |
| Spin-orbit ratio | 3:2 (3 rotations per 2 orbits) |
| Solar day (sunrise to sunrise) | 176 Earth days |
| Orbital eccentricity | 0.206 - highest of the eight planets |
Next: the when guide or vs alternatives. Open the Mercury Spin-Orbit Resonance 3D Explorer.
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