Venus is a scientifically rich target for exploration.The evolution of Venus is, at present, poorly known, despite it being our closest planetary neighbor. This book reviews current knowledge of how Venus formed, evolved, and reached its current state. It is not clear how its tectonic and volcanic activity has varied through history, nor whether it once had a habitable phase with liquid water on its surface. Science questions addressed in the book span interior processes, surface geology, the atmosphere, climate, evidence for current activity, and the potential for past habitability. 

Venus is also critical to planetary sciences in a broader sense. What lessons can we learn about the history of life and habitability on Earth-sized planets and terrestrial planets in general, whether in our solar system or elsewhere? The book addresses how increased study of Venus will also advance our understanding of critical questions for astrobiology, comparative planetology, and the processes that shaped the early Earth.

Now is a pivotal time in Venus exploration. New discoveries from Venus Express and Akatsuki, and new analyses of Magellan and earlier missions, have yielded a wealth of new insights into the evolution of Venus. Three new Venus missions have recently been selected - EnVision by ESA, DAVINCI and VERITAS by NASA - which will revolutionize our understanding of the current state of Venus and its evolution through time, and other mission concepts are in development. This book outlines how upcoming missions and related investigations will provide data needed to piece back together what caused Earth and Venus to evolve so differently.

Reprinted from Space Science Reviews Topical Collection "Venus: Evolution Through Time".