It has this extraordinarily dense atmosphere that by all accounts shouldn't exist - Venus is close enough to the sun (and therefore hot enough) that the atmosphere should have literally evaporated away, just like Mercury's. We think Earth manages to keep its atmosphere by virtue of our magnetic field, but Venus doesn't even have that going for it. While Venus is probably volcanically active, it definitely doesn't have an internal magnetic dynamo, so whatever form of volcanism it has going on is very different from ours. And, it spins backwards! For some reason!!

But, for as many mysteries as Venus has, the United States really hasn't spent much time investigating it. The Soviet Union, on the other hand, sent no less than 16 probes to Venus between 1961 and 1984 as part of the Venera program - most of them looked like this!

The Soviet Union had a very different approach to space than the United States. NASA missions are typically extremely risk averse, and the spacecraft we launch are generally very expensive one-offs that have only one chance to succeed or fail.

It's lead to some really amazing science, but to put it into perspective, the Mars Opportunity rover only had to survive on Mars for 90 days for the mission to be declared a complete success. That thing lasted 15 years. I love the Opportunity rover as much as any self-respecting NASA engineer, but how much extra time and money did we spend that we didn't technically "need" to for it to last 60x longer than required?

Anyway, all to say, the Soviet Union took a more incremental approach, where failures were far less devastating. The Venera 9 through 14 probes were designed to land on the surface of Venus, and survive long enough to take a picture with two cameras - not an easy task, but a fairly straightforward goal compared to NASA standards. They had…mixed results.

Venera 9 managed to take a picture with one camera, but the other one's lens cap didn't deploy.

Venera 10 also managed to take a picture with one camera, but again the other lens cap didn't deploy.

Venera 11 took no pictures - neither lens cap deployed this time.

Venera 12 also took no pictures - because again, neither lens cap deployed.

Lotta problems with lens caps.

For Venera 13 and 14, in addition to the cameras they sent a device to sample the Venusian "soil". Upon landing, the arm was supposed to swing down and analyze the surface it touched - it was a simple mechanism that couldn't be re-deployed or adjusted after the first go.

This time, both lens caps FINALLY ejected perfectly, and we were treated to these marvelous, eerie pictures of the Venus landscape: