Cosmic Flybys May Have Triggered Earth’s Mass Extinctions, New Theory Suggests
A new preprint by Daniele Fargion proposes that flybys of planetary-mass objects in the outer Solar System could generate strong tides, volcanism, and climate upheavals on Earth, contributing to past mass extinctions beyond the Chicxulub event. The idea emphasizes tidal effects from near-passages (not direct collisions) and links several geological anomalies to such events; the hypothesis is controversial and based on correlations in the geological record. The paper, presented in 2025 and available on arXiv, underscores the possibility that distant, massive objects occasionally influence Earth’s history.
