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Updated: May 4, 2026

Simulation of the Planetary Interior Differentiation Processes in the Laboratory
Published on: November 15, 2013
Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems
1Department of Physics and Astronomy and Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, IL 60208; and y-lithwick@northwestern.edu.
Abstract:
In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.
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