Gary sent in the link https://www.sciencealert.com/venus-appears-to-be-a-churning-hotbed-of-volcanic-activity … Venus appears to be a churning hotbed of volcanic activity. A re-analysis of data seems to indicate heavy volcanic actitivity was actually going on when the Magellan orbiter, back in the 1990s, was passing around the planet. Some changes on the surface, picked up by the analysis, can best be attributed to volcanism and upwelling of magma. What they are saying is that volcanic activity on Venus is ongoing. One reason why it is hot.
Its surface temperature is 30 times that of Earth and its pressure is 90 times greater. It has an extrmeely thick atmosphere. What caused this?