scholarly journals Rates of protoplanetary accretion and differentiation set nitrogen budget of rocky planets

2021 ◽  
Author(s):  
Damanveer S. Grewal ◽  
Rajdeep Dasgupta ◽  
Taylor Hough ◽  
Alexandra Farnell
1997 ◽  
Vol 161 ◽  
pp. 203-218 ◽  
Author(s):  
Tobias C. Owen

AbstractThe clear evidence of water erosion on the surface of Mars suggests an early climate much more clement than the present one. Using a model for the origin of inner planet atmospheres by icy planetesimal impact, it is possible to reconstruct the original volatile inventory on Mars, starting from the thin atmosphere we observe today. Evidence for cometary impact can be found in the present abundances and isotope ratios of gases in the atmosphere and in SNC meteorites. If we invoke impact erosion to account for the present excess of129Xe, we predict an early inventory equivalent to at least 7.5 bars of CO2. This reservoir of volatiles is adequate to produce a substantial greenhouse effect, provided there is some small addition of SO2(volcanoes) or reduced gases (cometary impact). Thus it seems likely that conditions on early Mars were suitable for the origin of life – biogenic elements and liquid water were present at favorable conditions of pressure and temperature. Whether life began on Mars remains an open question, receiving hints of a positive answer from recent work on one of the Martian meteorites. The implications for habitable zones around other stars include the need to have rocky planets with sufficient mass to preserve atmospheres in the face of intensive early bombardment.


2016 ◽  
Vol 50 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Tomohiro Usui ◽  
Audrey Bouvier ◽  
Justin I. Simon ◽  
Noriko Kita

Author(s):  
Sosuke OTANI ◽  
Tomoya YASHIKI ◽  
Kenta UEMURA ◽  
Kunihiro TOKUDA ◽  
Kohei FUJISHIMA ◽  
...  

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0121432 ◽  
Author(s):  
Emilie R. Kirk ◽  
Chris van Kessel ◽  
William R. Horwath ◽  
Bruce A. Linquist

2021 ◽  
Author(s):  
Riccardo Pozzobon ◽  
Diana Orlandi ◽  
Carolina Pagli ◽  
Francesco Mazzarini

<p>Volcanic activity is widespread within the inner Solar system and it can be commonly observed on rocky planets.<br>In this work, we analyse the structures of Pavonis Mons, which is one of the three large volcanoes in the Tharsis volcanic province of Mars, by performing structural mapping, azimuth, and topographic distribution of linear features on the flanks of Pavonis, such as grabens and pit chains. We tested whether their formation is to be ascribed to the internal volcano dynamics and magmatic activity or the tectonics related to the Tharsis volcanic province activity.<br>Through the length size distribution and fractal clustering analyses of the structural features, we found that large grabens are vertically confined in the upper mechanical layers of the brittle crust whereas pit chains penetrate the whole crust up to the magmatic source, indicating that they can be considered the main feeders of Pavonis Mons. We inverted the topography with dykes and faults models to test whether grabens at the surface are the expression of intrusions at depth and we suggest that thin dykes inducing normal faulting is the most likely mechanism. Furthermore, two azimuthal distribution of the grabens are identified: concentric grabens occur on the volcano summit while linear grabens at its base show NE-SW trend as the Tharsis Montes volcanoes alignment. The analyses show that faults related to large grabens are confined in a mechanical layering in the upper layers of the brittle crust, whereas deeper structures such as pit chains are most likely associated to magma injection/dykes and therefore, connected to the subcrustal magma source at a depth of ~80–100 km.<br>Therefore, based on our results, we infer that Pavonis Mons recorded active rifting at the initial stages of development with the formation of the large linear graben and faults at its base followed by a phase of volcano growth and concentric magma intrusions when volcano and magma chamber dynamics prevailed</p>


2021 ◽  
Author(s):  
Claire Delon ◽  
Corinne Galy-Lacaux ◽  
Blandine Barret ◽  
Ousmane Ndiaye ◽  
Dominique Serça ◽  
...  

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