Hesperian
Sign in to saveThe Hesperian is a geologic system and time period on the planet Mars characterized by widespread volcanic activity and catastrophic flooding that carved immense outflow channels across the surface. The Hesperian is an intermediate and transitional period of Martian history. During the Hesperian, Mars changed from the wetter and perhaps warmer world of the Noachian to the dry, cold, and dusty planet seen today. The absolute age of the Hesperian Period is uncertain. The beginning of the period followed the end of the Late Heavy Bombardment and probably corresponds to the start of the lunar Late
Key facts
- Geologic timespan.name
- Hesperian
- Geologic timespan.manual_color
- rgb(255.0, 51.0, 51.0)
- Geologic timespan.top_bar
- mars
- Geologic timespan.time_start
- 3700
- Geologic timespan.time_end
- 3000
- Geologic timespan.latest
- 2000
- Geologic timespan.top_bar_ps
- (upper bound uncertain – between about 3200 and 2000 million years ago)
- Geologic timespan.image_outcrop
- Hesperia Planum.jpg
- Geologic timespan.caption_outcrop
- MOLA colorized relief map of Hesperia Planum, the type area for the Hesperian System. Note that Hesperia Planum has fewer large impact craters than the surrounding Noachian terrain, indicating a younger age. Colors indicate elevation, with red highest, yellow intermediate, and green/blue lowest.
- Geologic timespan.subdivisions
- Early Heperian Late Hesperian
- Geologic timespan.celestial_body
- mars
- Geologic timespan.timescales_used
- Martian Geologic Timescale
- Geologic timespan.chrono_unit
- Period
- Geologic timespan.strat_unit
- System
- Geologic timespan.type_section
- Hesperia Planum
via Wikipedia infobox
Article
8 sectionsContents
- Description and name origin
- Hesperian chronology and stratigraphy
- System vs. period
- Boundaries and subdivisions
- Mars during the Hesperian Period
- Impact cratering
- Notes and references
- Bibliography and recommended reading
The Hesperian is a geologic system and time period on the planet Mars characterized by widespread volcanic activity and catastrophic flooding that carved immense outflow channels across the surface. The Hesperian is an intermediate and transitional period of Martian history. During the Hesperian, Mars changed from the wetter and perhaps warmer world of the Noachian to the dry, cold, and dusty planet seen today. The absolute age of the Hesperian Period is uncertain. The beginning of the period followed the end of the Late Heavy Bombardment and probably corresponds to the start of the lunar Late Imbrian period, around 3700 million years ago (Mya). The end of the Hesperian Period is much more uncertain and could range anywhere from 3200 to 2000 Mya, with 3000 Mya being frequently cited. The Hesperian Period is roughly coincident with the Earth's early Archean Eon.
With the decline of heavy impacts at the end of the Noachian, volcanism became the primary geologic process on Mars, producing vast plains of flood basalts and broad volcanic constructs (highland paterae). By Hesperian times, all of the large shield volcanoes on Mars, including Olympus Mons, had begun to form. Volcanic outgassing released large amounts of sulfur dioxide (SO2) and hydrogen sulfide (H2S) into the atmosphere, causing a transition in the style of weathering from dominantly phyllosilicate (clay) to sulfate mineralogy. Liquid water became more localized in extent and turned more acidic as it interacted with SO2 and H2S to form sulfuric acid.