Nectarian

Nectarian is a term used in lunar geology to denote a specific interval in the Moon’s geologic timescale. The name is derived from the Nectaris Basin, one of the prominent impact basins whose formation helps to define this period. In standard lunar stratigraphy, the Nectarian sits between the Pre-Nectarian and the Imbrian, marking a phase after the earliest solidification of the lunar crust and before the major basin-forming events that characterize the Imbrian.

The Nectarian period is characterized by a relatively high rate of large-impact events, which produced several major basins and extensive impact melt and ejecta blankets across the lunar highlands. The surface records are dominated by craters and fractured terrain resulting from bombardment that reworked earlier crustal materials. Radiometric ages from lunar samples and crater counting support a time frame roughly around 3.92 to 3.85 billion years ago, though precise boundaries can vary slightly among interpretations.

In scientific use, the Nectarian serves as a key reference point for correlating lunar surfaces with one another and for calibrating cratering chronology. It provides a framework for understanding early lunar evolution, the history of impact flux in the inner solar system, and the temporal sequencing of surface processes on the Moon. The term is widely employed in planetary geology and is part of the broader scheme that regions on the Moon and other airless bodies use to infer relative and absolute ages.