背景
Around 2.023 billion years ago, a large celestial body struck what is now South Africa. The Vredefort Dome is the eroded centre of one of Earth's largest confirmed impact structures. Shocked minerals and intensely deformed rocks provide evidence of the collision; the original diameter is uncertain because erosion has removed much of the crater. The map shows the present-day location, not the continent's position at the time.
资料来源： NASA — Vredefort Crater