Roche Limit Calculator

d = R_primary * (2 * rho_primary / rho_satellite)^(1/3)

Primary Body Radius (km)

Primary Body Density (kg/m^3)

Satellite Density (kg/m^3)

Formula

d_rigid = R(2rho_p / rho_s)^(1/3) | d_fluid = 2.44R(rho_p / rho_s)^(1/3)

What is the Roche limit?

The Roche limit is the closest distance a body held together only by gravity can orbit without being torn apart by tidal forces.

Why are there rigid and fluid limits?

Rigid bodies resist deformation, so their Roche limit is closer. Fluid bodies deform more easily and break up farther away.

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