EARTH

The Largest Crater on Earth

~2.02 billion years ago

Proterozoic · Paleoproterozoic · Orosirian

A body some twenty kilometres across struck what is now South Africa and left a crater around 250 kilometres wide. Erosion has taken the rim; what shows today is the crater's floor, deep crust heaved up by the rebound, with the gold of the Witwatersrand basin beside it.

Why it matters

Chicxulub, the impact that ended the dinosaurs, was less than half this size. Vredefort is what the early Earth took routinely, and recovered from.

Dating & uncertainty

The age of the Vredefort structure is well constrained at 2.02 Ga. What has changed is its size: simulations that reproduce the shocked minerals now call for an impactor of 20 to 25 km, rather than the 15 km that had long been assumed, and a crater near 250 km across.

Sources

1. Allen et al. (2022), Journal of Geophysical Research: Planets · A revision of the formation conditions of the Vredefort crater
2. Marchi et al. (2024), Earth and Space Science · Impact-generated permeability and hydrothermal circulation at the Vredefort impact structure
3. Henkel & Reimold (1998), Tectonophysics · Integrated geophysical modelling of a giant, complex impact structure

Earth history as one day

13:19:1710 h 41 min before midnight

if Earth’s 4.54 billion years were compressed into a single day