Without seismic data or knowledge of its moment of inertia, little direct information is available about the internal structure and geochemistry of Venus.
The similarity in size and density between Venus and Earth suggests they share a similar internal structure: a core, mantle, and crust.
Like that of Earth, the Venusian core is at least partially liquid because the two planets have been cooling at about the same rate.
The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth's.
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.

Instead, Venus may lose its internal heat in periodic major resurfacing events.
Without seismic data or knowledge of its moment of inertia, little direct information is available about the internal structure and geochemistry of Venus. The similarity in size and density between Venus and Earth suggests they share a similar internal structure: a core, mantle, and crust. Like that of Earth, the Venusian core is at least partially liquid because the two planets have been cooling at about the same rate. The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth's. 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.
Instead, Venus may lose its internal heat in periodic major resurfacing events.
Venus