Could We Have Cloud Cities On Venus Before Cities On Mars?
Say colonising Mars all goes to pot. The whole SpaceX/Nasa collaboration completely flops, Earth is on it’s last legs and in order to survive, humanity needs to go somewhere else. Where’s the next best place? Well, it would have to be Venus. Only problem is that Venus’ surface temperature is a casual 467 C. So what do we do?
Well, since the 20th century, the idea of colonisng Venus has been explored in science fiction. Obviously don’t take these ideas as gospel in their entirety, but a lot of the stories written have bases in scientific theory. A lot of the early novels center around terraforming the planet, with notable examples including the Olaf Stapleton’s 1930 work Last And First Men. Two chapters are dedicated to describing humanity’s descendants terraform Venus after Earth becomes uninhabitable and destroy the local aquatic life in the process.
By the middle of the century, terraforming Venus was becoming commonplace in sci-fi. Poul Anderson wrote a lot about it in the 1950s; his book The Big Rain becoming so influential that the term ‘Big Rain’ become synonymous with terraforming the planet.
In 1991, author Kim Stanley Robinson became famous for realistically depicting terraforming in his Mars Trilogy. He followed this series up in 2012 with 2312, a novel that discussed the colonisation of the Solar System, including Venus. It also explored how Venus could be terraformed, including global cooling and carbon sequestration. They were all based on scholarly studies and proposals.
There’s a clear trend here, and that is the act of planetary engineering in order to make the planet habitable. However, there have been other suggestions too, ones that don’t involve mass environmental change. According to Inner Solar System: Prospective Energy and Material Resources, Soviet scientists have proposed the idea of living in Venus’ atmosphere rather than trying to change the surface since the 1970s. This idea was also central in the paper by NASA scientist Geoffrey A. Landis. He proposed a city above the clouds:
“[T]he atmosphere of Venus is the most earthlike environment (other than Earth itself) in the solar system. It is proposed here that in the near term, human exploration of Venus could take place from aerostat vehicles in the atmosphere, and that in the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus.”
The theory comes from the pressure of the atmosphere. At about 50km above the surface, Venus’ atmosphere has a pressure of 100,000 Pa, slightly less than the 101,325 Pa of Earth at sea-level. Cosmic radiation would be deflected by the atmosphere above, and temperatures range from 0 to 50C. Power would come from solar energy. But the kicker comes in the form of Venus’ air.
Venus has a dense carbon dioxide atmosphere, and this means that ‘Earth-air’ (a 21:79 oxygen-nitrogen mix) has 60% of the lifting power helium has on Earth. The living spaces for colonists could use aerostats filled with this air, allowing the living areas to float above the clouds.
The living spaces for colonists could use aerostats filled with this air, allowing the living areas to float above the clouds.
Having floating cities also would produce the knock-on effect of cooling the planet’s surface by intercepting the Sun’s rays. The cities could also deploy chemicals into the atmosphere in efforts to make the surface more hospitable. This could possibly come in the form of a hydrogen aerosol which produces graphite and water. The latter would fall to the surface as rain and cover an estimated 80% of the surface in oceans.
As of 2015, NASA has begun exploring mounting crewed missions to Venus as part of its ‘High Altitude Venus Operational Concept’ (HAVOC). But as of recent, it seems that Mars has taken priority. Whilst this is by no means a bad thing, I’d love to see the colonisation of Venus via floating cities.