Geologic map of Meridiani Planum, Mars

First posted January 31, 2017 Revised April 28, 2017 For additional information, contact: Contact Astrogeology Research Program staff Astrogeology Science CenterU.S. Geological Survey 2255 N. Gemini Dr. Flagstaff, AZ 86001 https://astrogeology.usgs.gov/ The Meridiani Planum region of Mars—originally named due to its proximity to the Martian prime meridian—contains a variety of geologic units, including those that are crater‑related, that span the Early Noachian to Late Amazonian Epochs. Mars Global Surveyor (MGS) data indicate this area contains extensive layered deposits, some of which are rich in the mineral hematite. The National Aeronautics and Space Administration's (NASA) Mars Exploration Rover (MER) Opportunity landed in Meridiani Planum in early 2004 and, at the time of this writing, is still conducting operations. A variety of water-altered bedrock outcrops have been studied and contain indications of prolonged surface and near-surface fluid/rock interactions. The purpose of this study is to use the more recent orbiter data to place the rover's findings in a broader context by assessing the geologic and hydrologic histories of the region.