Fargion Ties 600 Million Years of Mass Extinctions to Planetary Flybys
Updated
Updated · ScienceAlert · Jun 24
Fargion Ties 600 Million Years of Mass Extinctions to Planetary Flybys
2 articles · Updated · ScienceAlert · Jun 24
Summary
A new preprint argues near-Earth flybys by planetary-mass objects or dwarf planets may have driven several major extinctions over the past 600 million years through extreme gravitational tides rather than direct impacts.
Fargion says those passages could trigger years-long mega-tsunamis, crustal deformation, volcanic eruptions, sea-level shifts and climate shocks—offering a possible explanation for extinctions lacking clear craters or iridium signatures.
The paper points to the Permian-Triassic die-off 251 million years ago, when 80% to 95% of species vanished, as a case where tidal disruption could fit better than a conventional impact scenario.
Evidence cited includes fossil corals suggesting a sudden Earth-Moon distance change at the end of the Devonian, which Fargion says a close flyby could explain more plausibly than a collision.
The hypothesis remains speculative: the work is an ArXiv preprint presented at a June 2025 conference, but it argues outer Solar System objects could still pose a distinct hazard requiring deep-sky monitoring.
Did a rogue planet's gravity, not an asteroid, cause the 'Great Dying' that wiped out 95% of life?
Are giant tidal waves from passing dwarf planets a bigger threat to humanity than asteroid impacts?
Does cosmic silence hint that gravitational flybys regularly reset evolution on worlds across the galaxy?
Rethinking Mass Extinctions: The Role of Planetary-Mass Object Flybys and Gravitational Tides in Earth’s History
Overview
Daniele Fargion's new hypothesis suggests that some of Earth's mass extinctions were caused by powerful gravitational tides from close flybys of planetary-mass objects or dwarf planets. These objects, which exist in the outer Solar System, can be drawn into the inner Solar System by gravitational perturbations. When they pass near Earth, their immense gravity creates strong tidal forces in the oceans, crust, and mantle, disturbing Earth's geological and climate systems. This can lead to massive tidal waves, volcanic eruptions, and dramatic environmental changes, offering a fresh explanation for the catastrophic events that have shaped life on our planet.