Editing Venus (section)

=== Internal structure ===
[[File:InteriorOfVenus.svg|thumb|upright=1.05|The [[Planetary differentiation|differentiated]] structure of Venus|alt=Spherical cross-section of Venus showing the different layers]]

Without data from [[reflection seismology]] or knowledge of its [[moment of inertia]], little direct information has been available about the internal structure and [[geochemistry]] of Venus.<ref name="goettel"/> The similarity in size and density between Venus and Earth suggests that they share a similar internal structure: a [[Planetary core|core]], [[Mantle (geology)|mantle]], and [[Crust (geology)|crust]]. Like that of Earth, the Venusian core is most likely at least partially liquid because the two planets have been cooling at about the same rate,<ref name=Faure_Mensing_2007/> although a completely solid core cannot be ruled out.<ref name=Dumoulin2017/> The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth's.<ref name=Aitta_2016/> The predicted values for the moment of inertia based on planetary models suggest a core radius of 2,900–3,450&nbsp;km.<ref name=Dumoulin2017/> There is now an estimate of 3,500&nbsp;km from the [[moment of inertia]] based on the rate of [[axial precession]], measured between 2006 and 2020.<ref name=Margot_et_al_2021/><ref name="O'Callaghan_2021"/>

The crust of Venus is estimated to be 40 kilometers thick on average and at most 65 kilometers thick.<ref>{{Cite journal |last1=Semprich |first1=Julia |last2=Filiberto |first2=Justin |last3=Weller |first3=Matthew |last4=Gorce |first4=Jennifer |last5=Clark |first5=Nolan |date=2025-03-25 |title=Metamorphism of Venus as driver of crustal thickness and recycling |url=https://www.nature.com/articles/s41467-025-58324-1 |journal=Nature Communications |language=en |volume=16 |issue=1 |pages=2905 |doi=10.1038/s41467-025-58324-1 |pmid=40133342 |bibcode=2025NatCo..16.2905S |issn=2041-1723|pmc=11937330 }}</ref>

The principal difference between the two planets is the lack of evidence for plate tectonics on Venus, possibly because its crust is too strong to [[subduct]] without water to make it less [[viscous]]. This results in reduced heat loss from the planet, preventing it from cooling and providing a likely explanation for its lack of an internally generated [[magnetic field]].<ref name=Nimmo_2002/> Instead, Venus may lose its internal heat in periodic major resurfacing events.<ref name="Nimmo98"/>