Theoretically, we could build floating cities on Venus:
Landis has proposed aerostat habitats followed by floating cities, based on the concept that breathable air (21:79 Oxygen-Nitrogen mixture) is a lifting gas in the dense carbon dioxide atmosphere, with over 60% of the lifting power that helium has on Earth. In effect, a balloon full of human-breathable air would sustain itself and extra weight (such as a colony) in midair. At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system – a pressure of approximately 1 bar and temperatures in the 0°C–50°C range.
Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates rather than an explosive decompression, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe, protection from the acidic rain and on some occasions low level protection against heat. Alternatively, two-part domes could contain a lifting gas like hydrogen or helium (extractable from the atmosphere) to allow a higher mass density.
Landis has proposed aerostat habitats followed by floating cities, based on the concept that breathable air (21:79 Oxygen-Nitrogen mixture) is a lifting gas in the dense carbon dioxide atmosphere, with over 60% of the lifting power that helium has on Earth. In effect, a balloon full of human-breathable air would sustain itself and extra weight (such as a colony) in midair. At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system – a pressure of approximately 1 bar and temperatures in the 0°C–50°C range.
Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates rather than an explosive decompression, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe, protection from the acidic rain and on some occasions low level protection against heat. Alternatively, two-part domes could contain a lifting gas like hydrogen or helium (extractable from the atmosphere) to allow a higher mass density.
http://en.wikipedia.org/wiki/Floating_city_(science_fiction)...
http://en.wikipedia.org/wiki/Colonization_of_Venus#Aerostat_...