Resources of the Solar System: Venus

Venus orbits the Sun at ~ 0.72 AU and receives roughly twice the insolation as Earth – with very low variation because its orbit is nearly circular. Its mass, radius and surface gravity are very close to our own – 0.815 Earth masses, 6052 km and 8.87 m/s^2 respectively. Its orbit around Sol lasts 243.1 Earth-days and its rotation on its axis is 224.7 Earth-days, but retrograde. This means the solar-day – time between sunrise and sunrise – is 116.8 Earth-days. Thus, without centrifugal force countering gravity, the Venusian globe is very nearly spherical, unlike all the other large planets, Earth and Mars included.

The most striking feature of Venus is its atmosphere – opaque, very reflective and very massive. By volume it’s 96.5% carbon dioxide and 3.5% nitrogen, and little dashes of everything else. The clouds are a practically unbroken haze of fuming sulfuric acid (H2SO4 + SO3 in solution with a bit of water) and opaque because they’re very deep, many kilometres. Surprisingly, if condensed, they would amount to only a few centimetres of acid. Beneath the haze banks the air is clear, though there are unidentified particles floating around that might be decomposed acid (i.e. grains of sulfur.) From the visible top-deck of the clouds to the surface is about 70 km and the surface pressure is a very high 92 bar. The surface temperature is ~ 735 K or 462 C/864 F, and would glow a dull red if the sunlight didn’t sufficiently penetrate the clouds to give a hellish eternal glow.

So what’s available on such a nasty planet? Let’s do an inventory

(1) Atmosphere – carbon dioxide is about a quarter carbon, which is the high-strength material of the future. Nitrogen is more abundant than on Earth – 2.7 times as much in fact. Combined the atmosphere could supply C,N,O for millions of space-cities, but that’s an as yet non-existent market.

(2) Surface – while hot there are materials that happily tolerate such conditions and retain strength, so teleoperated machines would work just fine, especially using high temperature electronics developed by the US DoD. Venus is similar in bulk density to Earth so its mineral resources will be akin, but differently distributed. Water has played a major role in concentrating ores on Earth, powered by plate tectonic processes. Venus doesn’t seem to have enough water in its mantle and upper crust for the same processes to occur. It might, however, do something completely different yet with similar results. We don’t yet know what so much water-free chemistry with a hot surface might do.

(3) Energy – deuterium is 150 times more prevalent than on Earth and might need removal from what hydrogen is available in the clouds to make potable water. Thus it’s a natural fusion fuel resource, though diffusely spread throughout the clouds. Above the cloud decks the energy flux from the Sun is almost twice Earth’s – and almost as much is reflected back up by the clouds as rains down from above. Thus solar energy is abundant.

(4) Gravity – Venus’s surface gravity is 90% Earth’s, so human health issues of ‘low gravity’ will be non-existent. Gravity also makes some industrial processes easier and that will be a boon.

(5) Space – at the 1 atmosphere level of the atmosphere Venus has 90% of Earth’s surface area, thus 3 times Earth’s dry-land area. Of course any colonies will need to float, but breathable N2/O2 mixtures are lighter than the ambient CO2/N2 mix. Thus vast inflated habitats will float naturally in the nicest part of the planet. The super-rotating atmosphere will mean the effective day-night cycle will be just 4 Earth days, not the 116.7 days of the rocks below. Thus a vast area for building habitats, if so desired.

(6) Any suggestions? Make a comment and let me know.