Until Now
GeologyCosmology

The South Pole–Aitken impact

The largest confirmed crater in the Solar System is punched into the far side of the Moon.

When
Known to
± 20 million years
Era
Hadean

An impact excavates a basin some 2,500 kilometres across and 8 kilometres deep, exposing material from the Moon's mantle. Samples returned by China's Chang'e-6 mission in 2024 date the event to about 4.25 billion years, making it the oldest anchor point for the crater-counting chronology used to date surfaces across the entire Solar System.

Just before

Just after