The Nectarian Period of the lunar geologic timescale runs from 3920 million years ago to 3850 million years ago. It is the period during which the Nectaris Basin and other major basins were formed by large impact events. Ejecta from Nectaris forms the upper part of the densely cratered terrain found in lunar highlands.

Since all geological evidence of that time on Earth has disappeared, it has been used as an unofficial period of the Hadean eon. The massive scale of the impact bombardment that occurred during this period of lunar history (dubbed the Late Heavy Bombardment) has affected virtually all older lunar material, and appears to have been an important event in the inner solar system. Significantly, the oldest surviving terrestrial rock strata formed shortly after the lunar Hadean period.

Lunar geologic periods

Nettariano | ネクタリス代 | Nektarij