By Dr. Gary Deel, Ph.D., J.D.
Faculty Director, School of Business, American Military University
This is the sixth article in a six-part series on the history of Venus space exploration and research, and the possibility of human colonization on Venus.
In the fifth article of this series, I discussed the viability of a ‘floating colony’ concept, which involves the creation of human habitats that would bob along in the clouds of Venus. Many experts believe this idea is a good one.
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However, researchers have also spent a lot of time and money investigating other options for colonization in the solar system, with the primary candidate being Mars. But how does Venus stack up against Mars on the subject of potential human habitability?
Venus vs. Mars Colonization
It’s worth noting that Venus would be more attractive for human colonization because of its proximity and size similarity to Earth. As our closest neighboring planet, trips to Venus would be the shortest possible in the solar system. Missions to Mars would take far longer and would be more expensive.
Because Venus is so close in size to Earth, humans visiting it would experience virtually the same gravity as here at home. This is particularly important because research on human spaceflight to date has indicated that long-term exposure to reduced gravity can be extremely hazardous to human health, with concerns over issues such as sensory impairment, muscle atrophy, and bone density loss. On Mars, the gravity would only be roughly 40 percent that of Earth’s, so long-term health effects would be a much more significant concern.
In terms of temperature and pressure, Venus also seems to take the cake. The warmest that Mars gets — on the equator in the summer months — is maybe about 50 degrees Fahrenheit. However, the equatorial temperature regularly dips to 80 or more below zero at night.
And in terms of pressure, unfortunately Mars has very little atmosphere to speak of. It is roughly one percent the density of Earth’s.
Humans would not be able to walk around on the surface of Mars without a pressurized spacesuit, because our blood would literally boil within our bodies due to lack of pressure. Compare this with Venus, which at about 31 miles’ altitude has both temperatures and pressures very similar to Earth’s. Venus is the clear winner here.
With regard to radiation protection, Venus wins for much the same reason. Both Mars and Venus lack strong planetary magnetic fields, and radiation from space is therefore uninhibited in reaching the planet itself.
However, Mars’s lack of atmosphere means that the radiation from space penetrates all the way through to the surface. But on Venus, this radiation is largely absorbed, scattered or deflected by the thick atmosphere, which means the lower layers are better protected for human colonization purposes.
With respect to water sourcing and oxygen, Mars is much more competitive, but there is a strong argument that Venus is still a superior choice. On Mars, water is actually plentiful…much more so than on Venus. It is frozen in very large quantities around the polar caps.
Recent research from missions on the red planet has indicated that water may flow just beneath the surface soil of Mars in areas where temperatures get high enough to allow for water to exist in liquid form. Sourcing water on Mars could be fairly easy.
But on the other hand, the process of electrolysis is a fairly simple one. Given that on Venus the sulfuric acid needed to make water literally rains down from the sky all over the planet, colonizing Venus could be a better alternative.
In regard to oxygen, air would presumably be made the same way on both planets through chemical processing (another type of electrolysis) of the carbon dioxide in each planet’s atmosphere. However, the atmosphere of Venus is very densely saturated with carbon dioxide, but on Mars, the atmosphere is very thin. So the process of producing sufficient quantities of oxygen for breathing on Venus would arguably be much easier.
As far as power generation is concerned, options for creating electrical power on the two planets are different but equally workable. As I discussed in a previous article, wind power would be a natural choice on Venus.
Mars’s negligible atmosphere means that it has very weak wind currents, but it also means that it enjoys permanently clear skies — barring the occasional dust storm — so solar power would be a strong option. In addition, nuclear power generators could serve as an alternative in either colonization scenario.
The final point of comparison between the two planets would be the manner of habitation. Cloud colonies on Venus would require the manufacture and deployment of enormous blimp-like structures that would support floating habitats. On Mars, colonies would ostensibly be ground-based, which initially sounds cheaper and less complicated.
However, because of the need for pressurized habitats with radiation shielding, habitats on Mars will have to be fairly complex and expensive in their own right. They will either have to be extremely well-engineered surface shelters, or they will need to be dug underground in order to use the terra firma as a natural insulation against radiation. Either way, colonization wouldn’t be as easy as simply pitching a tent after touchdown.
Additional Research and Investment Needed to Explore Viability of Venus Colonization
It seems that not only is the colonization of Venus possible, but it may in fact be the most appealing option we have for future off-world colonization, for reasons ranging from efficiency to practical viability. But if we are to truly explore this idea moving forward, what kind of additional research would be needed in order to prepare for such missions?
Fortunately, we already have a fairly good start on understanding a lot of the basic processes that would go into creating a self-sustaining colony in the Venusian atmosphere. But what we need is more research on Venus’s atmosphere to ensure we thoroughly understand all the dynamics at work there.
We should also perform heavy research into durable, inflatable balloon technology and habitats resistant to sulfuric acid. If we can develop well-thought-out prototypes for the spacecraft and any floating apparatus, a Venusian mission could realistically be launched within another decade.
We have come a long way in our understanding of Venus and its circumstances. Although it appears to be a very hostile place at first glance, a more careful analysis of the planet reveals that it might hold the promise of a viable option for human colonization; it may even be the best chance we have for moving off-world in the immediate future.
However, such an undertaking would require an unprecedented commitment to investment in research, in order to make sure that we thoroughly understand all of the challenges that future Venusian colonists might face. The last thing we would ever want to do is send human explorers to another world without all of the necessary preparation and contingency planning.
But if we take our existential need to spread off-world seriously and if we remember that we as a species are capable of greatness when we commit ourselves, there is no reason that Venus could not be a future home for mankind.
About the Author
Dr. Gary Deel is a Faculty Director with the School of Business at American Military University. He holds a J.D. in Law and a Ph.D. in Hospitality/Business Management. Gary teaches human resources and employment law classes for American Military University, the University of Central Florida, Colorado State University and others.