Effects of Shape and Spin on the Tidal Disruption of P/Shoemaker-Levy 9

  • A. W. Harris


I derive an approximate criterion for the tidal disruption of a “rubble pile” body as it passes close to a planet (or the sun):
$$ \rho _{c} \approx \left [ 2 \rho_{p} \left ( {R_{p}} \over {r} \right )^{3} + \left ( {\omega} \over \omega_{0} \right )^{2} \right ] \left ( {a} \over {b} \right ), $$
where ρ c is the critical density below which the body will be disrupted, ρ p is the density of the planet (or sun), R p is the radius of the planet, r is the periapse distance, ω is the rotation frequency of the body, ω0 is the surface orbit frequency about a body of unit density, and a/b is the axis ratio of the body, considered as a prolate ellipsoid. For P/Shoemaker Levy 9, in its passage close to Jupiter in 1992, this expression suggests that the critical density is ∼1.2 for a spherical, non-spinning nucleus, but could be >2.5 for a 2:1 elongate body with a typical rotation period of ∼10 hours.


Circular Orbit Axis Ratio Prolate Spheroid Comet Nucleus Disruption Criterion 
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Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • A. W. Harris
    • 1
  1. 1.Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaUSA

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