Orbital mechanics · d ≈ 2.44 R (ρ_M / ρ_m)^(1/3)

Roche Limit (fluid)

The distance within which a fluid satellite held together only by gravity is pulled apart by tides. Inside the Earth–Moon fluid Roche limit — about 18,000 km — a Moon-like body could not survive.

Primary radius (R⊕)Primary density (kg/m³)Satellite density (kg/m³)

Roche limit18365km

Formula: d ≈ 2.44 R (ρ_M / ρ_m)^(1/3)

Worked example

With the default inputs, roche limit (fluid) evaluates to 18365 km — Earth–Moon (fluid) → ~18,000 km. The validator recomputes this against the known value on every build, so the formula is checked, not asserted.

Highlights

›Earth–Moon: ~18,000 km

The Roche Limit

Knowledge connections

Associated withThe Roche Limit

Sources

Facts on this topic will be cited from these primary and reference sources.

NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
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Roche Limit (fluid)

Worked example

Highlights

The physics behind it

Knowledge connections

Sources

Roche Limit (fluid)

Worked example

Highlights

The physics behind it

Knowledge connections

Sources