Needless to say, these early missions unveiled a world that could not have been more different from the lush oasis some had hoped Venus might be. The Venera series, along with select Mariner probes, revealed instead a raging inferno, with surface temperatures of around 467 Celsius (872 degrees Fahrenheit), hot enough to melt lead, and pressures equivalent to the seafloor at a depth of one kilometer.

Electrically charged droplets of sulfuric acid circulate through the suffocating clouds, while a phenomenon called super-rotation whips the upper atmosphere into a vicious global hurricane that sweeps around the planet every four Earth days, with winds of 400 kilometers (250 miles) per hour.