On the right side of the image is a partially imaged crater with a well-preserved ejecta blanket. It is believed that this basin is the result of a large impact. GEOPS – Géosciences Paris Sud, Univ.(Released ) The Science This image is located in Utopia Planitia, a large plain in the northern hemisphere. Implications of an impact origin for the martian hemispheric dichotomy. Mega-impact formation of the Mars hemispheric dichotomy. Numerical modeling of the ejecta distribution and formation of the Orientale basin on the Moon. A crater and its ejecta: an interpretation of Deep Impact. Impact Cratering: A Geologic Process (Oxford Univ. Evidence for extremely rapid magma ocean crystallization. Origin and age of the earliest Martian crust from meteorite NWA 7533. Evidence for magmatic evolution and diversity on Mars from infrared observations. Petrological constraints on the density of the Martian crust. Global spectral classification of Martian low-albedo regions with Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) data. In situ evidence for continental crust on early Mars. Concentration of H, Si, Cl, K, Fe, and Th in the low- and mid-latitude regions of Mars. An origin for the linear magnetic anomalies on Mars through accretion of terranes: implications for dynamo timing. A new model of the crustal magnetic field of Mars using MGS and MAVEN. A coherent model of the crustal magnetic field of Mars. The global magnetic field of Mars and implications for crustal evolution. Late Tharsis formation and implications for early Mars. Evaluation of the orogenic belt hypothesis for the formation of the Thaumasia highlands, Mars. Evidence for a low bulk crustal density for Mars from gravity and topography. Seasonal and static gravity field of Mars from MGS, Mars Odyssey and MRO radio science. The tidal-rotational shape of the Moon and evidence for polar wander. Garrick-Bethell, I., Perera, V., Nimmo, F. Evidence for lunar true polar wander and a past low-eccentricity, synchronous lunar orbit. The shape and internal structure of the Moon from the clementine mission. South Pole–Aitken basin ejecta reveal the Moon’s upper mantle. Distribution of Early, Middle, and Late Noachian cratered surfaces in the Martian highlands: implications for resurfacing events and processes.
Internal structure and early thermal evolution of Mars from Mars Global Surveyor topography and gravity. The global topography of Mars and implications for surface evolution. Sequence and timing of conditions on early Mars. Mars without the equilibrium rotational figure, Tharsis, and the remnant rotational figure. The Borealis basin and the origin of the martian crustal dichotomy. Degree-1 convection in the Martian mantle and the origin of the hemispheric dichotomy. Degree-1 mantle convection and the crustal dichotomy on Mars. Large impact basins and the mega-impact origin for the crustal dichotomy on Mars. The martian hemispheric dichotomy may be due to a giant impact. Such a complex architecture of the southern highlands is not explained by existing scenarios for crustal formation and evolution. Our findings suggest that the southern highlands are composed of several crustal blocks with different geological histories. This region, corresponding to Terra Cimmeria–Sirenum, is interpreted as a discrete crustal block. However, our reconstruction reveals a region of discontinuous patches of thick crust in the southern highlands associated with magnetic and geochemical anomalies. Our reconstruction shows more subdued crustal thickness variations than at present, although the crustal dichotomy persists. Here we present reconstructions of the past crustal thickness of Mars (about 4.2 Gyr ago) where the four largest impact basins (Hellas, Argyre, Isidis and Utopia) are removed, assuming mass conservation, as well as the main volcanic provinces of Tharsis and Elysium. Previous studies have quantified the contribution of volcanism to this crustal structure however, the influence of large impacts remains unclear. The southern highlands are commonly treated as a coherent terrain of ancient crust with a common origin and shared geologic history, plausibly originating from a giant impact(s) or a hemispheric-scale mantle upwelling. The global-scale crustal structure of Mars is shaped by impact basins, volcanic provinces, and a hemispheric dichotomy with a thin crust beneath the northern lowlands and a thick crust beneath the southern highlands.
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