Copernician

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Periods of Lunar geologic time :

Pre-Nectarian - Nectarian - Lower Imbrian - Upper Imbrian - Eratosthenian - Copernician

The Copernician Period in the lunar geologic timescale runs from approximately 1100 million years ago to the present day. The moon's internal geologic activity is thought to have effectively ceased by the beginning of the Copernican, and lunar processes were driven by surface bombardment. The Copernican encompasses the era during which the Moon's bright-rayed craters were formed, of which the crater Copernicus is a prominent example. The date of this crater's formation marks the beginning of the Copernician Period.

The bright streaks that radiate from young Lunar craters such as these are formed from fresh ejecta blasted out of the crater by the impact that formed it. Almost all craters likely have such rays immediately after they form, but over time additional impacts and micrometeor "weathering" cause the rays to fade. Thus, only relatively recent craters still have visible rays; the older craters' rays having eroded away. The most prominent ray system visible on the lunar near side is from the late Copernican crater Tycho. The division between Copernician era craters and earlier craters is thus somewhat arbitrary.

Its Earth equivalents are the Neoproterozoic era of the Proterozoic eon and the whole of the Phanerozoic eon. So, while animal life bloomed on Earth, Luna just died out.