J/AJ/161/187ivo://CDS.VizieR/J/AJ/161/187doi:10.26093/cds/vizier.51610187CDSMarchi S.2022-03-16T11:45:44Z2021-09-23T06:38:17ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsolar-systemsolar-system-planetsCrater chronologies are a fundamental tool to assess the relative and absolute ages of planetary surfaces when direct radiometric dating is not available. Martian crater chronologies are derived from lunar crater spatial densities on terrains with known radiometric ages, and thus they critically depend on the Moon-to-Mars extrapolation. This extrapolation requires knowledge of the time evolution of the impact flux, including contributions from various impactor populations, factors that are not trivially connected to the dynamical evolution of the early Solar System. In this paper, we will present a new Martian crater chronology based on current dynamical models, and consider the main sources of uncertainties (e.g., impactor size-frequency distribution; dynamical models with late and early instabilities, etc.). The resulting "envelope" of Martian crater chronologies significantly differs from previous chronologies. The new Martian crater chronology is discussed using two interesting applications: Jezero crater's dark terrain (relevant to the NASA Mars 2020 mission) and the southern heavily cratered highlands. Our results indicate that Jezero's dark terrain may have formed ~3.1Ga, i.e., up to 0.5Gyr older than previously thought. In addition, available crater chronologies (including our own) overestimate the number of craters larger than 150km on the southern highlands, suggesting either that large craters have been efficiently erased over Martian history or that dynamical models need further refinement. Further, our chronology constrains the age of Isidis basin to be 4.05-4.2Ga and that of the Borealis basin to be 4.35-4.40Ga; these are predictions that can be tested with future sample and return missions.2021AJ....161..187Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/187CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/582/A36 : USNO Martian observations (Robert+, 2015)J/A+A/603/A55 : WISE/NEOWISE Mars-crossing asteroids (Ali-Lagoa+, 2017)J/A+A/614/A15 : Mars Express astrometric obs. of Martian moons (Ziese+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/187https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/187http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/187https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/187https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/187http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/187GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/161/187/figure2Combined table from original tablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeType of craterstat.fit.paramcharAgeAgeGyrtime.agedoubleNcratersNumber of craters/km^2^km**-2meta.numberdoubleJ/AJ/161/187/figure3Combined table from original tablesTypeType of craterstat.fit.paramcharAgeAgeGyrtime.agedoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNcratersNumber of craters/km^2^km**-2meta.numberdoubleJ/AJ/161/187/figure5Combined table from original tablesTypeType of craterstat.fit.paramcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDiamCrater diameterkmphys.size.diameterdoubleMPFModel production fonction (arbitrary units)stat.paramdouble