Thermal effects of impact bombardments on Noachian Mars
نویسندگان
چکیده
a United States Geological Survey, Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA b Collaborative for Research in Origins (CRiO), Department of Geological Sciences, University of Colorado, UCB 399, 2200 Colorado Avenue, Boulder, CO 80309-0399, USA c Institute for Geological and Geochemical Research, Research Center for Astronomy and Earth Sciences, Hungarian Academy of Sciences, 45 Budaörsi Street, H-1112 Budapest, Hungary
منابع مشابه
Noachian and more recent phyllosilicates in impact craters on Mars.
Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the No...
متن کاملCrater degradation in the Noachian highlands of Mars_ Assessing the hypothesis of regional snow and ice deposits on a cold and icy early Mars
The presence of valley networks and the highly degraded state of Noachian highland craters has led to the interpretation that Mars was once warmer and wetter. Recent climate models have suggested, however, that the extremely cold climate in the Noachian would be unlikely to support liquid water precipitation. The presence of a thicker atmosphere thermally coupled to the surface is predicted ins...
متن کاملAge and Origin of the Crustal Dichotomy in Eastern Mars
The topography associated with the fundamental crustal dichotomy in much of eastern Mars can be largely ascribed to a single event: the very large impact which produced the Utopia Basin. Subsequent internal and surficial processes have been unable to remove the topographic signature of this basin. In particular, endogenic processes appear to have been ineffective in contributing to the basic di...
متن کاملIdentification of Primary Noachian Crustal Blocks on Mars with Crism
Introduction: The nature, origin and evolution of Mars' Noachian crust is relatively unknown [1]. Detailed analyses of meteorites point to an early differentiation event for the planet but the only rock definitively of Noachian age is the Martian meteorite; ALH84001, comprised of >95% orthopyroxene [2]. Our understanding of the composition of the Martian crust is derived mostly from Amazonian-a...
متن کاملEvidence for Buried “pre-noachian” Crust Pre-dating the Oldest Observed Surface Units on Mars
MOLA gridded data shows clear evidence for Quasi-Circular Depressions not visible on images in Early Noachian (EN) terrain units on Mars. We suggest these are buried impact basins that pre-date the superimposed craters whose high density makes these EN units the oldest visible at the surface of Mars. There is crust older than the oldest visible terrain units on Mars, and these EN units cannot d...
متن کامل