The cloud cities of Venus

The best real estate in the Solar system besides Earth itself. [Link]

However, Venus holds a secret — it has some of the most Earth-like conditions (that we know of) in the Solar System. 50km above the rocky, smoking surface the atmospheric pressure is the same as on Earth, and average temperatures rarely exceed 50°C or drop below zero. The atmosphere — 96 percent carbon dioxide — is so dense that large metal structures filled with the nitrogen and oxygen mix we call ‘air’ would float with half as much lifting power on Venus as helium has here.

It’s not just zeppelins that would fly on Venus — it’s entire buildings.

Importantly, because there is no need for pressurisation, any leaks would be no more disastrous than opening a door in a house and letting out heat. Rips,tears, holes of any kind can be monitored and repaired long before they cause any deflation issues.

OK, the sulphuric acid rain is a bit of an issue, but nevertheless, it’s not too dissimilar to the conditions you’ll find within the calderas of volcanoes on Earth, and would only require similar breathing apparatus and protective clothing as volcanologists use. More than any other planet in the Solar System, Venus — with its Earth-like gravity, too — would feel the most like home. This is why NASA’s Geoffrey Landis calls it “the paradise planet”.

In 1985, The Soviet Union’s Vega program managed to deploy two balloons into the Venusian atmosphere at 53km above the surface, so we already have some data to go on. Wind speeds were seen to go as high as 340km/h — that’s fast, but not as fast as the 395km/hm world speed record for fastest balloon flight set by the Pacific Flyer in 1991.

At those speeds, our balloon colonies would circle Venus roughly every eight Earth days, relative to the surface — a further bonus since a typical Venusian day is longer than the Venusian year, taking 243 Earth days. We’d get our energy from the Sun (since we’d be high enough for it to break through the clouds), and our Earth calendar would only subtly have to be adjusted.

Be honest with yourself: the floating sky cities of Venus sound much more glamorous than coldly clinging to the dead rock of Mars. Think how restricted scientists are when living in Antarctica — any tin can bolted to the face of Mars will be lucky to give its residents anything like that much freedom. On Venus, we could conceivably build larger, faster, and further — and we could use our experience in the Venusian clouds to colonise the gas giants of the Solar System. In the long run, starting nearer to Earth could take us further.