000005253 001__ 5253
000005253 005__ 20210201174656.0
000005253 0247_ $$2DOI$$a10.1029/2020GL089895
000005253 037__ $$aSCART-2021-0051
000005253 100__ $$aSteinbrügge, G. 
000005253 245__ $$aChallenges on Mercury's interior structure posed by the new measurements of its obliquity and tides
000005253 260__ $$c2020
000005253 520__ $$aWe present calculations of interior models of Mercury that are constrained to match Mercury's mean density, normalized moment of inertia factor (MoI), and 88-day libration amplitude. We show that models matching a MoI=0.333$\pm$0.005, based on a recent obliquity measurement require a new perspective on Mercury's interior. Specifically, we confirm the mandatory presence of a large inner core > 600 km in radius which, however, leads to lower mantle densities in comparison to previous models and implies a mantle with > 5wt.{\%} C, > 10wt.{\%} MgS, or is partially convecting. Furthermore, we also show that the core radius is lower than previous estimates, making it inconsistent with current estimates from magnetic induction measurements. In addition, the requirement of low viscosities in the lower mantle to match recent estimates of k2 imply a significantly weaker mantle than previously believed, potentially including partial melting.
000005253 536__ $$a3PRODPLANINT/$$c3PRODPLANINT/$$f3PRODPLANINT
000005253 594__ $$aNO
000005253 700__ $$aDumberry, M. 
000005253 700__ $$aRivoldini, A. 
000005253 700__ $$aSchubert, G. 
000005253 700__ $$aCao, H. 
000005253 700__ $$aSchroeder, D. M. 
000005253 700__ $$aSoderlund, K. M.
000005253 773__ $$pGeophysical Research Letters$$y2020
000005253 8560_ $$fattilio.rivoldini@observatoire.be
000005253 905__ $$ain press to
000005253 980__ $$aREFERD