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Jack Wisdom is a planetary scientist whose work applies Hamiltonian mechanics, chaotic dynamics and numerical methods to the motion of bodies in the Solar system. His MIT profile documents contributions to long-duration integrations and mapping methods for planetary motion.^[ref]

His 1983 study of the three-to-one Kirkwood gap investigated how an orbital resonance with Jupiter can produce large changes in an asteroid's orbital eccentricity. It compared a simplified mapping with direct numerical integration, showing that the sudden eccentricity changes were not merely artifacts of the faster model.^[ref]

The three-to-one label means that an asteroid completes approximately three orbits for one orbit of Jupiter. Using Kepler's third law in an ideal solar two-body approximation givesThis locates the resonance approximately; it does not by itself establish that every trajectory there is unstable. The dynamical calculation asks how repeated perturbations alter the orbit over time. That distinction connects a simple period ratio to the harder problem of explaining an observed depletion of asteroids.