Hesperian

This is an excerpt from the content

Definition

The middle of three systems (of time-stratigraphic units) or periods (the chronologic equivalents to systems) in the Martian stratigraphic scheme, named after the region of Hesperia Planum (Hesperia: “The Occident”; see U.S. Geological Survey Gazetteer of Planetary Nomenclature). Depending on the different models to determine absolute ages on planetary surfaces by Crater statistics, the Hesperian began ∼3.8 billion years ago and ended at some point between 3.55 and 1.8 billion years ago.

See also

Amazonian

Chronology, Cratering and Stratography

Crater, Impact

Hesperian

Mars

Mars Stratigraphy

Noachian