New research
shows it's the composition of the rock a meteorite hits, and not the impactor's size, that causes an extinction-level event.
© ESA - P.CarrilNear-Earth objects pass by our planet in this artist's rendering.
It's a well-known story in our planet's past: A giant space rock slams into Earth, causing a catastrophe that ends in mass extinction. You might think that when it comes to determining
which hits will cause such widespread devastation, the size of the incoming impactor is what matters.
But new research suggests that something else might matter more: The composition of the ground where that meteorite hits.The work, published Dec. 1, 2021, in
Journal of the Geological Society, focuses on explaining why some meteorite impacts cause mass extinctions, while others don't. For example, the famous impact that killed the dinosaurs and left the
Chicxulub crater was much smaller than many other impact events that didn't cause massive loss of species. Why might this be?