OK, so chemistry and physics are not my strong suit, so this idea is just cobbled together from stuff I've heard can be done. But I'd be curious if it is at all plausible, and what the most likely pitfalls would be.


  1. Set up a hydrogen mining platform on Jupiter.
  2. Harvest iron from as near as possible (not sure if there is enough iron dust around Jupiter, or if it would have to come from further afield. I suppose there is no practical way to get iron and nickel from the core with the crazy pressures down there).
  3. Get the iron/iron ore to the $\require{mhchem}\ce{H2}$ mining platform.
  4. Fabricate $\ce{H2}$ filled iron spheres.
  5. Use a rail gun to shoot them out of Jupiter's gravity, on a trajectory to intersect with Venus.

Expected results:

  1. The iron spheres would burn up or react with $\ce{H2SO4}$ in the Venusian atmosphere.
  2. The temperature will be high enough for the $\ce{H2}$ and $\ce{CO2}$ to react, and the disintegrating iron from the sphere would catalyze a Bosch reaction, producing $\ce{H2O}$ and graphite.

Reasons why this might be a good idea:

  1. Scalable. Experimental $\ce{H2 - Fe}$ spheres could be made near Earth, shot at Venus, and the effect measured, so the reaction could be tested and optimized.
  2. Swarm based. The fate of any individual sphere matters little, making the system more resilient to space debris.
  3. The magnetic properties of the spheres could be harnessed to minimize the cost of propelling the spheres to Venus.
  4. Could probably be fully automated.

Reasons why this might be a bad idea.

  1. The magnetic launch of the spheres might not practical. This plan depends on it being feasible and cost effective to hurl the spheres at Venus such that they do not need propulsion systems of their own. I imagine a hose $\ce{H_2 - Fe}$ bubbles squirting Venus from across the Solar System, but it is late at night and my imagination may be getting the better of me.
  2. It might be too hard to target the spheres, even if they could be shot across the Solar System at low cost. Too many might miss. What would happen if some rained on Earth?
  3. The $\ce{Fe}$ could be eaten up by the $\ce{H2SO4}$ in the upper atmosphere of Venus, preventing it from acting as a catalyst.

Added questions for clarity:

  1. How much energy would it take to launch H2 filled iron spheres from Jupiter's orbit across the solar system to Venus? Assuming they are on the order of a few grams to a few kilograms each.
  2. How fast would they have to be shot in order that their path not be overly disrupted by the gravitational pull of other objects on their way their (say, to get 50% of the spheres to fall on Venus.
  3. What would be the optimal ratio of $\ce{H2}$ pressure inside to thickness of the iron sphere?
  4. Would an $\ce{Fe}$ sphere filled with $\ce{H2}$ falling into the Venusian atmosphere as a meteor be expected to produce a Bosch reaction?
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    $\begingroup$ What's preventing Venus to continue with its runaway greenhouse effect and again lose hydrogen to Jeans escape? You would need to first construct / arrange for a huge sunscreen for the whole Venus. And that iron dust would be much easier to obtain on Mars, it's literally covered with it (thus the color). Otherwise, nothing much is wrong with your scheme, except that you'd somehow have to find a way to substantially decelerate those hydrogenated iron pebbles not to release too much energy in ionosphere and we'd need to climb a few rungs on the Kardashev scale, to be able to do any of that. $\endgroup$ – TildalWave Jul 19 '15 at 7:42
  • $\begingroup$ Technology and energy, especially at the scale necessary to make an impact. $\endgroup$ – NPSF3000 Jul 19 '15 at 9:37
  • $\begingroup$ The value of having a second Earth can maybe be estimated as the sum of all real estate plus the value of all output from agriculture and mining on Earth, ever. $\endgroup$ – LocalFluff Jul 19 '15 at 11:46
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    $\begingroup$ What is the question exactly? $\endgroup$ – mins Jul 23 '15 at 19:46
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    $\begingroup$ Iron would more likely come from asteroid mining. Energy cost would be the delta V to get out of Jovian orbit, plus delta V to reduce your perihelion to intercept the Venusian (or Venerean, if you prefer) orbit at the point where Venus is going to be there, which will change as the alignments of the planets change. -- More importantly, though, this question should be split up into different, more focused questions. $\endgroup$ – Ghedipunk Aug 19 '15 at 22:13