Case file · Cosmic event
Vredefort Dome
The Vredefort Dome south-west of Johannesburg is the eroded core of the largest verified impact structure on Earth, made by an asteroid about two billion years ago; UNESCO listed it in 2005.
2005 CE · -27.00, 27.50 · status: official
The account
The original crater may have been around 300 km across. Shocked quartz and shatter cones in the rocks confirmed its impact origin, long debated against a volcanic one.