000006457 001__ 6457
000006457 005__ 20230428150219.0
000006457 0247_ $$2DOI$$a10.1073/pnas.2217090120
000006457 037__ $$aSCART-2023-0148
000006457 100__ $$aIrving, Jessica C. E. 
000006457 245__ $$aFirst observations of core-transiting seismic phases on Mars
000006457 260__ $$c2023
000006457 520__ $$aWe present the first observations of seismic waves propagating through the core of Mars. These observations, made using seismic data collected by the InSight geophysical mission, have allowed us to construct the first seismically constrained models for the elastic properties of Mars? core. We observe core-transiting seismic phase SKS from two farside seismic events detected on Mars and measure the travel times of SKS relative to mantle traversing body waves. SKS travels through the core as a compressional wave, providing information about bulk modulus and density. We perform probabilistic inversions using the core-sensitive relative travel times together with gross geophysical data and travel times from other, more proximal, seismic events to seek the equation of state parameters that best describe the liquid iron-alloy core. Our inversions provide constraints on the velocities in Mars? core and are used to develop the first seismically based estimates of its composition. We show that models informed by our SKS data favor a somewhat smaller (median core radius = 1,780 to 1,810 km) and denser (core density = 6.2 to 6.3 g/cm3) core compared to previous estimates, with a P-wave velocity of 4.9 to 5.0 km/s at the core?mantle boundary, with the composition and structure of the mantle as a dominant source of uncertainty. We infer from our models that Mars? core contains a median of 20 to 22 wt{\%} light alloying elements when we consider sulfur, oxygen, carbon, and hydrogen. These data can be used to inform models of planetary accretion, composition, and evolution.
000006457 536__ $$a3PRODPLANINT/$$c3PRODPLANINT/$$f3PRODPLANINT
000006457 594__ $$aNO
000006457 700__ $$aLekić, Vedran 
000006457 700__ $$aDurán, Cecilia 
000006457 700__ $$aDrilleau, Mélanie 
000006457 700__ $$aKim, Doyeon 
000006457 700__ $$aRivoldini, Attilio 
000006457 700__ $$aKhan, Amir 
000006457 700__ $$aSamuel, Henri 
000006457 700__ $$aAntonangeli, Daniele 
000006457 700__ $$aBanerdt, William Bruce 
000006457 700__ $$aBeghein, Caroline 
000006457 700__ $$aBozdağ, Ebru 
000006457 700__ $$aCeylan, Savas 
000006457 700__ $$aCharalambous, Constantinos 
000006457 700__ $$aClinton, John 
000006457 700__ $$aDavis, Paul 
000006457 700__ $$aGarcia, Raphaël 
000006457 700__ $$anull, Domenico Giardini 
000006457 700__ $$aHorleston, Anna Catherine 
000006457 700__ $$aHuang, Quancheng 
000006457 700__ $$aHurst, Kenneth J. 
000006457 700__ $$aKawamura, Taichi 
000006457 700__ $$aKing, Scott D. 
000006457 700__ $$aKnapmeyer, Martin 
000006457 700__ $$aLi, Jiaqi 
000006457 700__ $$aLognonné, Philippe 
000006457 700__ $$aMaguire, Ross 
000006457 700__ $$aPanning, Mark P. 
000006457 700__ $$aPlesa, Ana-Catalina 
000006457 700__ $$aSchimmel, Martin 
000006457 700__ $$aSchmerr, Nicholas C. 
000006457 700__ $$aStähler, Simon C. 
000006457 700__ $$aStutzmann, Eleonore 
000006457 700__ $$aXu, Zongbo
000006457 773__ $$n18$$pProceedings of the National Academy of Sciences$$v120$$y2023
000006457 8560_ $$fattilio.rivoldini@observatoire.be
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000006457 905__ $$apublished in
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