Interiors of Earth-Like Planets and Satellites of the Solar System
Spohn, Tilman
Van Hoolst, Tim
van Westrenen, Wim
Stanley, Sabine
Rambaux, Nicolas
DOI: https://doi.org/10.1007/s10712-021-09677-x
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11040
Spohn, Tilman; DLR Institut für Planetenforschung, Berlin, Germany
Van Hoolst, Tim; Institute of Astronomy, KU Leuven, Leuven, Belgium
van Westrenen, Wim; Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
Stanley, Sabine; Department of Erath and Planetary Sciences, John Hopkins University, Baltimore, MD, USA
Rambaux, Nicolas; Institut de Mécanique Céleste et des Ephémérides, Observatoire de Paris, CNRS, PSL Research University, Sorbonne Université, Université de Lille, Paris, France
Abstract
The Earth-like planets and moons in our solar system have iron-rich cores, silicate mantles, and a basaltic crust. Differentiated icy moons can have a core and a mantle and an outer water–ice layer. Indirect evidence for several icy moons suggests that this ice is underlain by or includes a water-rich ocean. Similar processes are at work in the interiors of these planets and moons, including heat transport by conduction and convection, melting and volcanism, and magnetic field generation. There are significant differences in detail, though, in both bulk chemical compositions and relative volume of metal, rock and ice reservoirs. For example, the Moon has a small core [~ 0.2 planetary radii (RP)], whereas Mercury’s is large (~ 0.8 RP). Planetary heat engines can operate in somewhat different ways affecting the evolution of the planetary bodies. Mercury and Ganymede have a present-day magnetic field while the core dynamo ceased to operate billions of years ago in the Moon and Mars. Planets and moons differ in tectonic style, from plate-tectonics on Earth to bodies having a stagnant outer lid and possibly solid-state convection underneath, with implications for their magmatic and atmosphere evolution. Knowledge about their deep interiors has improved considerably thanks to a multitude of planetary space missions but, in comparison with Earth, the data base is still limited. We describe methods (including experimental approaches and numerical modeling) and data (e.g., gravity field, rotational state, seismic signals, magnetic field, heat flux, and chemical compositions) used from missions and ground-based observations to explore the deep interiors, their dynamics and evolution and describe as examples Mercury, Venus, Moon, Mars, Ganymede and Enceladus.
Subjects
Interior structureTerrestrial planets and moons
Space exploration
Gravity
Rotation
Magnetic fields
Thermal evolution