For almost 25 years until 1985, the Soviet Union carried out an ambitious program, called Venera, to explore Venus. It included, among other things, orbiting radar mapping, landers to investigate the ground and hovering balloons that checked the characteristics of the atmosphere.
The Venusian environment is infernal, so all human-made devices that descended into the clouds perished within hours or days. Still, the Venera probes provided us much with of what we know today of our nearest planetary neighbor. Even though the program ended thirty years ago, it is still worth to take a look at.
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