Orbital Mechanics
Forces, Equilibria & Resonance
Lagrange Points
Five Equilibria in Every Two-Body System
Every pair of orbiting bodies shares five gravitational equilibrium points. Two are stable — objects placed there stay indefinitely. Three are unstable but strategically valuable.
Orbital Resonance
Period Locking & Resonance Chains
When orbital periods form simple integer ratios, repeated gravitational nudges lock bodies into stable — or destabilising — resonance chains.
Roche Limit
Tidal Disruption & Ring Formation
The critical orbital distance inside which tidal forces overwhelm a body's self-gravity, tearing it apart and spreading its remains into a ring system.
Tidal Locking
Synchronous Rotation & Permanent Hemispheres
How tidal forces gradually brake a body's spin until rotation and orbit synchronise, permanently fixing one face toward the primary.
Kepler's Laws
Three Rules That Govern Every Orbit
The foundations of orbital mechanics: orbits are ellipses, equal areas are swept in equal times, and period squared scales with semi-major axis cubed.
Hill Sphere
The Region of Gravitational Dominance
The radius around a body where its gravity wins over the parent's. Sets the limit on stable moons, captured satellites, and why close-in planets can't hold companions.
This module treats motion as a readable system: every orbit is shaped by force, energy, angular momentum, resonance, and the limits of gravitational control.
The simulations are built to make invisible mechanics visible, from equilibrium points to the tidal forces that sculpt rings and locked worlds.