What was the Pre-Nectarian period on the Moon?

The Pre-Nectarian period is the earliest geologic period in the history of Earth's Moon, spanning from its initial formation 4.533 billion years ago until the creation of the Nectaris Basin 3.920 billion years ago. It marks the foundation of the lunar geologic timescale, followed subsequently by the Nectarian period. The boundaries and events of this deep era are understood through the study of lunar impacts and the radiometric dating of samples.

What we know

• The pre-Nectarian period of the lunar geologic timescale began 4.533 billion years ago with the initial formation of the Moon. [1, 2]
• The period ended 3.920 billion years ago when the Nectaris Basin was formed by a large impact. [2]
• The lunar geologic timescale divides the Moon's history into five periods, of which Pre-Nectarian is the earliest. [4]

Still open

• There is ongoing debate concerning the exact ages of certain key events in the lunar geologic timescale because correlating lunar regolith samples with geological units is difficult.

Where to go next

• whenWhat follows the Pre-Nectarian period?
• the bigger pictureHow is the lunar geologic timescale divided?
• what caused itDid a Late Heavy Bombardment reshape the inner solar system?
• how it workedHow does radiometric dating constrain absolute ages on the Moon?
• a case in pointWhat major impact formed the Nectaris Basin?
• an unexpected connectionHow do Earth's early eras align with lunar history?The hypothesized Late Heavy Bombardment during late lunar formation corresponds directly to the Neohadean and Eoarchean eras on Earth.

Sources

• [1]Pre-Nectarian (Wikidata Q630370) · CC0 1.0
• [2]Pre-Nectarian · CC BY-SA 4.0
• [3]Late Heavy Bombardment · CC BY-SA 4.0
• [4]Lunar geologic timescale · CC BY-SA 4.0
• [5]Timeline of Earth · CC BY-SA 4.0