Home▸Space & Astronomy▸The Roche Limit: Where Tides Beat Gravity

🪐 The Roche Limit: Where Tides Beat Gravity

Interactive 3D planet-moon system where shrinking a moon's orbital distance shows tidal forces overcoming its self-gravity once it crosses the simulated Roche limit, tearing it apart.

Space & Astronomy3DModerate60 FPS

A moon made of hundreds of individually-orbiting rock chunks holds together as a rigid sphere until it crosses the red Roche-limit shell — then differential Keplerian motion shears it apart into a debris ring.

🔬 What It Demonstrates

Inside the Roche limit, tidal stretching from the planet overwhelms the moon's self-gravity. Because chunks closer to the planet orbit faster than chunks farther out (Kepler's third law), the moon shears itself apart rather than being "pulled" apart in one direction.

🎮 How to Use

Drag the orbital distance slider inward past the red shell and watch the moon disperse; pull back out and it slowly re-coheres. Adjust moon/planet density to see the Roche limit itself grow or shrink, or let "Auto spiral-in" do the dragging for you.

💡 Did You Know?

Saturn's rings are thought to be the remains of a moon (or moons) that wandered inside the Roche limit and never re-accreted, leaving a flat disc of ice and rock instead.

⚙ Under the hood

Interactive 3D planet-moon system where shrinking a moon's orbital distance shows tidal forces overcoming its self-gravity once it crosses the simulated Roche limit, tearing it apart.

roche-limittidal-forcestidal-disruptionorbital-mechanicsastronomy

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install