Tidal Forces (Why There Are Two Bulges)

Put a planet next to a moon or a star and see how gravity pulls the near side harder than the far side — the stretch that raises two tides a day, locks the Moon's face to us, and can tear a moon apart if it strays too close.

Still frame from the Tidal Forces (Why There Are Two Bulges) simulation
Requires Interstellar

What you can adjust

System
0 – 4

Pick a real planet/moon/star pair, or go Custom and set every mass, radius and separation yourself.

Tide-raiser mass (Custom only)
20 – 30.477121 log₁₀(kg)

How massive the body doing the pulling is, on a log scale (10^value kg) — only used when System is set to Custom.

Stretched body's radius (Custom only)
1 – 5.90309 log₁₀(km)

The radius of the body being stretched, on a log scale (10^value km) — only used when System is set to Custom.

Stretched body's mass (Custom only)
20 – 27.30103 log₁₀(kg)

The mass of the body being stretched, on a log scale (10^value kg) — only used when System is set to Custom.

Separation
0.30103 – 5.477121 log₁₀(× tide-raiser radii)

How far apart the two bodies are, as a log-scale multiple of the tide-raising body's own radius — drag it down far enough and the stretched body crosses its own Roche limit.

Animation duration
4 – 8 s

How long the clip runs — long enough to watch the stretched body complete one full orbit.