After 16 years of painstaking work, the U.S. Geological Survey has released a series of geologic maps that offer the most thorough representation of the Red Planet's surface to date. The revealing project will help mission planners target future areas for robotic — and potentially human — exploration.
The USGS is no stranger to producing otherworldly maps. Back during the Apollo Moon landings the organization compiled lunar maps for NASA. Some four decades later, the USGS has turned its attention to Mars.
The geologic map, which is available here, was created using the instruments on board the Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter spacecraft. The high-quality data sets generated by these probes allowed the mission scientists to re-map the global scale geology of Mars in unprecedented detail.
The mapping effort reveals that the Martian surface is older than previously thought. Approximately three times as much surface area dates to the planet's first major geologic time period than previously mapped, the so-called Early Noachian Epoch. This period, which is the earliest part of the Noachian Epoch, ranges from about 4.1 to about 3.7 billion years ago. This era was characterized by high rates of meteorite impacts, widespread erosion of the Martian surface, and the likely presence of abundant surface water. In total, the Noachian makes up 45% of the surface, the Hesperian 29%, and the Amazonian 26%.
The map also confirms the hypothesis that Mars was once a geologically active place. There's evidence that major changes in Mars's global climate supported the presence of surface water and near-surface groundwater and ice. Over time, these changes were responsible for major shifts in the environment where Martian rocks formed and eroded. The new maps will serve as a key reference for the origin, age, and historic change of geological materials anywhere on the planet.
In addition, all impact basins greater than 150 km in diameter have been dated and show a dramatically reduced rate of formation over time.
And as noted, the maps will inform future missions.
"Findings from the map will enable researchers to evaluate potential landing sites for future Mars missions that may contribute to further understanding of the planet's history," noted USGS Acting Director Suzette Kimball in a statement. "The new Mars global geologic map will provide geologic context for regional and local scientific investigations for many years to come."
Read the entire scientific paper here.
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