# Noachian epoch

> English word · Proper noun

## Definitions
1. The earliest of the Martian geologic epochs, approximately from 3,800 million years ago to 3,500 million years ago, marked by many large impact craters and followed by the Hesperian epoch.

## Etymology
Named for Noachis Terra.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/noachian-epoch