Ancient stellar flyby may still be steering long-period comets today

The Gaia mission has allowed researchers to understand the motions of stars like never before, even revealing possible interactions between our solar system and nearby stars. Planetary Science Institute Senior Scientist Nathan Kaib and collaborator Sean Raymond (Universite de Bordeaux) have found that a recent stellar passage likely triggered a huge increase in comet formation as the star's gravity altered Oort cloud objects' orbits, sending them cascading into the inner solar system. We may even still be feeling the effects of this passage today. This work is being presented at the American Astronomical Society Division on Dynamical Astronomy.