Sinus Meridiani
[1] The name Sinus Meridiani was given to a classic albedo feature on Mars by the French astronomer Camille Flammarion in the late 1870s.Prior astronomers, notably the German team of Wilhelm Beer and Johann Heinrich von Mädler and then the Italian Giovanni Schiaparelli, had chosen a particular point on Mars as being the location of its prime meridian when they charted their observations.Accepting suggestions that dark areas on the surface of Mars were seas or oceans, Flammarion named a dark area at that point "Sinus Meridiani," literally "Meridian Bay," when he worked on his compilation and analysis of all prior observations of Mars.On the other hand, a small amount of hematite that was present meant that there may have been liquid water for a short time in the early history of the planet.Few rocks were visible on the surface where Opportunity landed, but bedrock that was exposed in craters was examined by the suite of instruments on the Rover.Similar high levels were found by other rovers at Ares Vallis and Gusev crater, so it has been hypothesized that the mantle of Mars may be phosphorus-rich.[14] When Opportunity traveled to the rim of the impact crater Endeavour, it found a white vein that was later identified as being pure gypsum.[15][16] It was formed when water was discovered to harbor a then-unknown gypsum formation, at the time dubbed "Homestake," deposited the mineral into a crack in the rock.Observations at the site have led scientists to believe that the area was flooded with water a number of times and was subjected to evaporation and desiccation.
albedo featureequatorastronomerCamille FlammarionWilhelm BeerJohann Heinrich von MädlerGiovanni Schiaparelliprime meridianInternational Astronomical Unionalbedo featuresMeridiani PlanumMars Exploration RoverOpportunityhematite2001 Mars Odysseylag deposittitanomagnetitemagnetiteolivineRock Abrasion ToolGusev cratersulfurmagnesium sulfateskieseritebassaniteepsomitegypsumhalitebischofiteantarcticiteblöditeglauberiteThermal Emission SpectrometerMars Global SurveyorAlpha particle X-ray spectrometerphosphorusAres Vallisbasalturaniumthoriumrare-earth elementsimpact craterEndeavourjarositelaminationscross-stratificationbromineTektitetektitespyroxeneplagioclaseEETA 79001meteoritesMini-TESMossbauer spectrometerIAB meteoritenickelmesosideriteHiRISEHiWish programGeography of MarsEagle CraterOutline of MarsGeographyAtmosphereCirculationClimateDust devil tracksMethaneRegionsArabia TerraCerberus (Mars)CydoniaEridania LakeIani ChaosOlympia UndaePlanum AustralePlanum BoreumQuadranglesTempe TerraTerra CimmeriaTerra SabaeaTharsisVastitas BorealisPhysicalfeatures"Canals"CatenaeChaos terrainCratersFossaeGulliesMensaeMountainsby heightObserved rocksOutflow channelsPlainsValley networkValleysGravityGeologyBrain terrainCarbonatesCompositionConcentric crater fillDark slope streakDichotomyFretted terrainGeysersGlaciersGroundwaterLava tubesLobate debris apronMarsquakeon Earthon MarsMud cracksNorth Polar BasinOcean theoryOre resourcesPolar capspolar wanderRecurring slope lineae (RSL)Ring mold cratersRootless conesSeasonal flows