Would it be theoretically possible to build a large habitable dome on the surface of Venus, one of the most inhospitable places in the solar system? (continued)
Damir Blazina
Chester, UK
Advertisement
I would like to mention an idea proposed by Soviet engineer Sergey Zhitomirskiy in the early 1970s and expanded on by NASA engineer in the 2000s. They suggested the use of aerostats, or lighter-than-air aircraft, for crewed exploration of Venus and potentially for the construction of permanent 鈥渃loud cities鈥� high up in the Venusian atmosphere.
This would be made possible by the high atmospheric pressure on Venus and the fact that its atmosphere is mostly carbon dioxide. Nitrogen and oxygen, the principal constituents of the atmosphere on Earth, are lighter than carbon dioxide, and a breathable mix of nitrogen and oxygen would have a lifting power of approximately 60 per cent of that of helium on Earth.
Landis calculated that a balloon full of human-breathable air could sustain itself and the extra weight of a colony at an altitude of about 50 kilometres above the surface of Venus.
At this altitude, the conditions are much more Earth-like: temperatures are in the region of 0掳C to 50掳C (32掳F to 122掳F) and the pressure is around 1 atmosphere.
As the aerostat would float rather than orbit, any crew would experience Venus鈥檚 0.904 g gravity, avoiding weightlessness-related issues. Any rips or tears in the balloon would cause gases to diffuse at normal atmospheric mixing rates rather than through explosive decompression, giving time to repair damage.
Finally, the remaining atmosphere above the balloon would provide shielding from cosmic rays, with its greater density giving comparable protection to that on the surface of Earth.
There are several remaining problems. For example, the aerostat would need to withstand the 200-kilometre-per-hour winds that blow at this altitude. Furthermore, all construction and industrial materials would have to be brought from Earth at significant cost, and would have to be resistant to corrosion by the sulphuric acid found in the atmosphere.
Despite these caveats, the concept is theoretically plausible and may even be practically possible. NASA published a concept study in 2015 for a crewed mission to explore the atmosphere of Venus, called , or HAVOC. To my knowledge, however, no craft has yet thoroughly explored the area 50 km above Venus鈥檚 surface.
Rod Newbery
Cambridge, UK
Venus is apparently at the temperature that it is because of a runaway greenhouse effect. Its hostile atmosphere has made studying it very difficult. Can we be certain it didn鈥檛 once have a civilisation that caused the greenhouse effect?
To answer this question 鈥� or ask a new one 鈥� email lastword@newscientist.com.
Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.
麻豆传媒 retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.