 The gravitational perturbations caused by frequent close approaches to the terrestrial planets lead to chaotic behavior in the orbit of Toutatis, making precise long-term predictions of its location progressively inaccurate over time.Estimates in 1993 put the Lyapunov time horizon for predictability at around 50 years, after which the uncertainty region becomes larger with each close approach to a planet.Without the perturbations from the terrestrial planets the Lyapunov time would be close to 10,000 years.