I think Ulric might like this one. It turns out, according to a new study, that minor planets in the asteroid belt have a chaotic effect on Earth’s orbit.
Astronomy & Astrophysics is publishing a new study of the orbital evolution of minor planets Ceres and Vesta, a few days before the flyby of Vesta by the Dawn spacecraft. A team of astronomers found that close encounters among these bodies lead to strong chaotic behavior of their orbits, as well as of the Earth’s eccentricity. This means, in particular, that the Earth’s past orbit cannot be reconstructed beyond 60 million years.
Strong chaos induced by close encounters with Ceres and Vesta, by J. Laskar, M. et al., Published in Astronomy & Astrophysics, 2011, vol. 532, L4
Full story at the link above