In his publication *Sidereus Nuncius*, what revelation did Galileo document regarding Venus?

Answer

That Venus went through a complete set of phases

Observing that Venus exhibited a full set of phases, similar to the Moon, was a direct confirmation of the Copernican model, as this is only geometrically possible if Venus orbits the Sun.

In his publication *Sidereus Nuncius*, what revelation did Galileo document regarding Venus?
Galileo GalileitelescopeAstronomerinstrumentOptic