We humans have long suspected that we are not alone; that the circumstances of our planet and our solar system are perhaps more ordinary than they might appear from our view of the night sky. For most of recorded history, humankind believed that the Earth was the sole oasis for life in an otherwise barren universe and center stage in the design of the cosmos.
In the first, second, and third articles in this series, I described Venus space research by the U.S. and USSR from the beginning of the space age to the 1980s. These two nations would be the only ones to pursue Venus research in the 20th century. But the new millennium has brought new participants to the Venus space exploration effort.