The overall geography of the Venusian surface has been determined largely by:

Question

Quizplus · Accepted Answer

Radar techniques from orbiting spacecraft have been the primary method for mapping the Venusian surface due to the thick clouds that obscure visible light photography and prevent unmanned spacecraft from landing on the surface. With radar, scientists have been able to create high-resolution maps of the surface and identify features such as mountains, valleys, and impact craters. This has allowed for a better understanding of the overall geography of Venus.

The Overall Geography of the Venusian Surface Has Been Determined