Guide to Space

How Do We Terraform Venus?

24 Jul , 2014 by Video

It might be possible to terraform Venus some day, when our technology gets good enough. The challenges for Venus are totally different than for Mars. How will we need to fix Venus?

This planet has been the center of corny nerd fantasies and awful behavioral gender oversimplifications from days of yore.

There are many real reasons to admire Venus from afar, but my favorite, much like Mars, is the potential to turn it into a vacation spot and haven for mad science planetary engineering. Venus is a virtual twin of Earth. It has a solid surface and very similar gravity to Earth.

You’re already sold, right? You can already picture yourself there in a sun hat on a beach towel. There’s are just few complications. There’s insane atmospheric pressure, clocking in at a hull crushing 91 atmospheres, and what’s worse for all this atmospheric trouble, there’s no oxygen. It’s a just a huge tank of suffocating CO2. It also rains sulfuric acid.

So, in order to terraform Venus, we need to decrease the temperature, reduce the thickness of the atmosphere, and there’s the simple matter of making breathable air. Here’s the best part. They’re all connected, and not a John Gray book in sight.

On Feb. 5, 1974, NASA's Mariner 10 mission took this first close-up photo of Venus during 1st gravity assist flyby. Credit: NASA

On Feb. 5, 1974, NASA’s Mariner 10 mission took this first close-up photo of Venus during 1st gravity assist flyby. Credit: NASA

Venus is so darned hot because of this thick CO2 atmosphere, the first thing we need to is cool the planet down. If you set up a huge space-based shade and block all sunlight from hitting the atmosphere, the temperature would drop, and I mean *drop*. It would cool hundreds of degrees until it was so cold the CO2 would freeze out of the atmosphere, and pile up in drifts on the ground. Then you could scoop up the carbon, bury it or shoot it off into space.

Another, equally mad idea would be to build floating cities high up in the atmosphere of Venus. They would need to contain factories which sucked carbon dioxide from the atmosphere and split it into carbon and oxygen. The carbon would be made into graphene structures, and the oxygen would become the lifting gas to keep the cities afloat. With more cities, it would block the sunlight and help cool the planet down.

Unfortunately, the slow rotation of the planet is still a big problem. A solar day on Venus is 116 Earth days in length. You could speed its rotation by close asteroid flybys, or use that crazy space shade contraption to create an artificial day/night cycle.

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL

This is but the tip of the CO2 iceberg. Here are the really crazy ideas. Start by smashing thousands of asteroids into the planet and splash the atmosphere into space. This plan has some flaws beyond the obvious engineering requirements and “Hail Mary” qualities. There’s a pretty good chance Venus would just scoop its atmosphere back up on the next orbit around.

You could also dump massive amounts of calcium or magnesium into the atmosphere to sequester the carbon away. Unfortunately, you’d need more mass than one of the largest asteroids we currently have available. There’s still that problem of no magnetic field, but I’m sure by the time we’ve worked out the first parts, that would seem like a walk in the park.

Terraforming Venus is insanely harder than terraforming Mars. But it’s still possible with enough planning, technology and patience, and that’s pretty amazing.

What do you think? Do we possess the capability to plan something this ambitious? Tell us in the comments below.
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By  -          
Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

16 Responses

  1. Aqua4U says:

    Floating sky cities maybe.. but terraforming all of Venus? Venus’ atmosphere is primarily CO2. Were we to figure out a way to easily break down that molecule to create an oxygen rich atmosphere and somehow blow off, collect or sequester the carbon, then maybe? BUT, it is possible that Venus is constantly producing CO2 via volcanic activity and therefor replenishing that greenhouse gas at far too high a rate to compensate for?

    • Denver says:

      Drop a world ocean (Europe, Ganymede) on it, come back in a few million years after the newly molten crust hardens.

    • FarAwayLongAgo says:

      Even successful terraforming doesn’t mean that it is livable for human beings. Earth itself has been livable for us only during a short period of time. Life started here with conditions which we cannot survive. Any living planet will have its own unique evolutionary path of life, atmosphere and geology. It is not enough to make a planet habitable, we have to make it a copy of present Earth in order to live there.

    • Kawarthajon says:

      Sorry to rain in on Fraser’s parade, but floating cities or factories won’t work on Venus. That’s because of the incredible wind speeds (“Strong 300 km/h (190 mph) winds at the cloud tops circle the planet about every four to five earth days” – wikipedia) and the much higher density of the atmosphere. Those combined would make it impossible for any large structure to survive, not to mention the sulfuric acid.

  2. CHUCK says:

    Dude, one Venus day is 243 earth day’s , not 116, interesting article though.

  3. tesla says:

    116 earth days is correct for a solar day which is the time from sunrise to sunrise, or sunset to sunset, or noon to noon, …

  4. paul roebling says:

    It takes Venus 243 Earth days to complete one revolution, but there are 116
    Earth days of sunlight. The article seems to imply that carbon dioxide is
    responsible for the hellish conditions on Venus – and that the Earth is next due
    to evil Republicans. Wrong! Venus is so hot because, with 116 days of sunlight,
    the surface of Venus heats up and carbon dioxide outgases from the surface.
    Also, Venus is closer to the Sun, and that would make Venus hot.

  5. FarAwayLongAgo says:

    Maybe heavy bench pressing and unbalanced training program has rotated Fraser’s shoulders forward in an unnatural way.

  6. Lynxworx says:

    I think the simplest way to get rid of the CO2 would be a little creative bioengineering. Create a bacteria with some plant genes (for photosynthesis), and seed Venus’ upper atmosphere. Assuming that their tiny mass would make them buoyant enough to stay in the upper atmosphere where the environment is more survivable (UV might be an issue, though), they could live off by metabolizing the CO2 and other chemicals in that environment, into O2 and other byproducts (which may either stay in the atmosphere or rain down on the planet’s surface.)

    • Richard Kirk says:

      Yep. Bioengineering, and make it excrete pure carbon in some dark inertish form such as buckytubes or graphite. The flakes of graphite would sink, raising the oxygen content in the atmosphere, and making the planet darker. You may then get large chemical convective storms as 2.CO2 -> 2.CO + O2 in the lower atmosphere and the reverse reaction in the relatively cool upper atmosphere. This would fetch heat from the surface to be radiated out into space.

      That, plus a reflector at the inner Lagrange point to block some of the sun.

    • eSpace says:

      @Lynxworx A very similar suggestion was published in Popular Science about 55 years ago (1959, as I recall… maybe April or May issue). The author at that time suggested seeding the upper atmosphere with a hardy strain of bluegreen algae which would feed on the CO2 and sunlight in the cooler atmosphere, releasing oxygen and shading the surface as it spread. Eventually the older algae would grow heavier and sink, burning up and dropping carbon residue. At some point, the author figured, it would be cool enough for rains to start and further clear the atmosphere and cool the surface. I remember reading this when I was about 10 years old and thought that it was such a great idea that it has stuck with me ever since. Thought it would be a good sci-fi story to have someone find a way to secretly stash a container on a Venus bound probe and release it high in the atmosphere.

  7. Aqua4U says:

    Sun screen, lots of sun screen… No really. All we have to do is wait several hundred million years or so.. then move on in. OR praps it won’t take that long? Solar output might change and strip Venus’s atmosphere much faster? Of course, if that happened, we’d be breathing vacuum here on Earth too?

    IF we ever succeed in terraforming Venus.. will there be Taco trucks?

  8. Tim Reyes says:

    “Days of yore”? Cut! … Yes, I’d have to try a second or third take, too. :) And while one might think a quick trip to the 420 apothecary might be in order, this is a tough problem requiring at least a few minutes of “real” clarity.

    Aqua4U, I’d agree with you that there must be a replenishing source for the CO2 and I would love to see the best paper on an Venusian atmospheric model that points to some X rate of CO2 production from the surface. Consider that even more brisk Solar Wind and Flux have been doing the same thing to Venus as with Mars, that is, without a magnetic field, stripping off the atmosphere for billions of years.

    Fraser’s accounting of hellish things one can do to a hellish environment makes one sense that there isn’t much harm one can do to this planet that would not be beneficial. The first funds for this project should go to pulling Gary Larson out of retirement to create a series of Venusian Farsides

    The idea of sequestering CO2 onto the surface by cooling doesn’t hold water. If Venus’s interior remains hot and active volcanism is common, a tug of war would ensue between the cooling and production of dry ice and reheating of the dry ice by surface rock. Iceland has such interactions. I would think that the dry ice would win but there would be many regions where the venu-thermal heat creates geysers – all kinds of outgassing.

    For Venus, I don’t buy the idea of impacting one or many asteroid or cometary objects. Too messy. This “terraforming” requires finesse. One alternative would be to move a cometary type object to the Venusian-Sun L1 point and let the Sun’s heat create a cooling shade from the outgassing of the object in front of Venus. It may not work as planned but it would be very cool looking for Earth observers!

    Another approach would be to declare CO2, plus energy, our friend. Rather than freeze out CO2, why not use a likely common element in the Venusian crust – Silicon to produce a completely stable and disposable compound – Silicon Carbide. There’s plenty of heat and Solar Flux and it would be needed. This would leave Oxygen that would be attractive to Earthlings but also generate some oxidative processes on the surface that would be interesting in the least.

    Next consider finishing what nature has not – despinning the planet. First, fix a single humongous propulsion system on the surface that would: 1) despin the planet, 2) propel Venus into an orbit at superior conjunction to the Earth (the opposite side of the Sun), 3) while doing all this thrusting, expel some amount of the CO2 atmosphere off the planet by way of the incredible thrust plume. Only problem with this orbit change is that one would have to do it in a single Hohman transfer orbit with an accompanying final thrusting maneuver to settle it into an Earth orbit; avoid fowling up the Earth’s orbit that we prize so highly. With that much propulsive energy at your disposal, you could choose to spin up the planet when ready.

    So what does one get after all this trouble? Take Lake Erie. Dry it out and propose putting track homes on its dry lake bed. One would have some serious concoction of chemicals on the surface, some just natural stuff and others from oxidation and from the heat added and subtracted from the system. Even if one created a 100,000 Pascal atmosphere with O2 and inert N2 (oh yeah), the chemical dust circulating in the atmosphere could be really toxic. So one would have a facsimile of an Earth environment and be stuck living under domes for centuries or millennium.

    So rather than vanquishing our beautiful evening and morning star by orbital mechanics and similarly destroy the incredible frozen deserts of Mars, why not produce the spherical habitats such as in Rendezvous with Rhama to offer humans a habitat beyond our surface. In the near term, inflated dome habitats made of thin film graphene on the Martian surface will be much more achievable – leaving most of Mars in its incredible natural state which is what attracts us to the planet in the first place. Elon Musk can retire in something more modest but his descendents would surely be something of Martian blue bloods.

    And the Earth during all this time when we could begin terraforming Mars or Venus would be undergoing a transformation. To Eden. Despite every generation over the last 2 millenium having several predicted apocalypses, we are still here. We huddle upon just 1/10th of our surface while having quadrupled our human population in just over 100 years. But this will change. Education, World communications and some inevitable technological advances will lead, despite some chaos along the way, to a shrinking of the population to maybe about 2 billion humans within 500 years. The Earth’s ecosystem will be restored and the comfort of home will make destinations such as orbiting habitats or domed colonies on Mars or the Moon incredible places to visit and for a few to live and become Martians or “Spacetians”. Human sub-species will develop but not necessarily inclined to procreate into billions.

  9. Cool thought, but I would say, economically infeasible. It would be easier to build an artificial planet than it would to terra-form Venus. Advantage of building an artificial planet is that it can start at a certain size and grow. Venus would be an all or nothing proposition. Venus might make a good source for materials, but then again there are asteroids already in space. Venus could be used as a gravity well for the artificial planet. Setting the rotation on the artificial planet would be a breeze. We would need to come up with some form of artificial gravity and atmosphere.
    I think that the first terraforming will actually be on the Moon. Mars is to far away, and, it would not make a good space port, because of the escape velocity. The Moons escape velocity is very low . . . . you would have plenty of fuel left after leaving the Moon. Asteroid mining is a cool idea, but to build spaceships anywhere other than on Earth, there will have to be some way to protect the builders from radiation exposure. Underground caverns on the Moon can accomplish that. The Moon has been proven to be very much like Earth, so chances are there will be plenty of the raw materials we would need.

  10. qraal says:

    An interesting question is just how much sulfuric acid there is in the clouds of Venus – according to one source there’s about ~5 milligrams of H2SO4 per cubic metre in the middle cloud deck. Thus a square metre frontal area exposed to a wind moving at 1 m/s will encounter 5 milligrams of acid per second. For comparison a cumulus water cloud on Earth has about 300 milligrams per cubic metre, thus the sulfuric acid clouds of Venus are comparatively thin.

    As for the 100-110 m/s winds of Venus, no one imagines the Cloud Cities will be anchored to the ground and expected to withstand such wind. Instead they’ll ride with it, producing a 4-day ‘sol’ rather than the surface’s 116 day sol. The danger isn’t windspeed, per se, but wind shear. And that’s much lower on Venus than Earth at the elevations of interest for floating colonies and bases.

    Aircraft on commercial routes, here on Earth, regularly fly with, across and against winds of such speeds in Earth’s tropopause. A suitable lifting body structure could be anchored to the ground and tap the wind for lift and power, assuming high temperature anchor cable up to the task.

    Total mass of sulfuric acid is about ~70-300 tonnes per square kilometre of surface. Sounds like a lot, but it’s much less than a millimetre of rain (=1,840 tonnes per square kilometre for sulfuric acid).

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