The Effect Of Stellar Flybys On The Perturbation Of Earth’s Orbit

The effect of stellar flybys on planetary bodies within our solar system is relatively unknown. Research suggests that changes in Earth’s orbit can affect the climatic evolution on our planet. These cycles, dubbed the Milankovitch cycles, have been cited as playing a role in the extinction events in Earth’s history. There is the potential that long term consecutive stellarflybys could alter the Milankovitch cycles. This may be a contributing factor in the extinction events that are associated with the crossing of the spiral arms. This study presents the effects of 34 flyby scenarios on the Earth’s eccentricity and inclination evolution. A number of REBOUND simulations were run over a 15 Myr period, passing stars of various masses at a variety of encounter distances, locations, and inclinations. The numerical models show that although many cases have little impact on the evolution of Earth’s eccentricity and inclination cycles, that coplanar flybys at distances < 50000 AU can change these cycles significantly. The results suggest that consecutive close encounters of stars to our solar system can perturb Earth’s orbit. Therefore, it is plausible that stellar flybys may influence the Milankovitch cycles and play a role in mass extinction events on Earth.