Since Mars has such a thin atmosphere, to Terraform we would need massive amounts of Nitrogen. Would it make sense to import it from Venus?

Also since venus's atmosphere is mostly co2, and we can make o2 from co2, could we just import o2 too? That might be faster than just creating o2 using plants on Mars.

  • $\begingroup$ Can you explain why you believe there is an advantage to moving mass quantities of N2 from Venus to Mars versus "using just plants"? Especially considering we have basically no way at present to do either? $\endgroup$ – Organic Marble Aug 24 '20 at 20:12
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    $\begingroup$ You might want to reconsider the biochemistry involved in using plants as a nitrogen source. And before you start transporting petatons of O2 across the solar system to Mars, you might want to see this chart: lpi.usra.edu/education/IYPT/Mars.pdf $\endgroup$ – Christopher James Huff Aug 24 '20 at 20:38
  • $\begingroup$ "and we can make O2 from CO2," Would that be on Venus, or on Earth ? Because it seems on Earth there's too much CO2 too. $\endgroup$ – Cornelisinspace Aug 24 '20 at 21:49
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    $\begingroup$ Atmospheric escape would take place over millions of years. As far as terraforming for human inhabitation is concerned, the problem is just moving enough gases. (And that's quite enough of a problem.) $\endgroup$ – Christopher James Huff Aug 26 '20 at 13:18
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    $\begingroup$ @CallMeTom I would guess we would have had a method to protect the atmosphere by then maybe similar as they proposed here phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html $\endgroup$ – Tracy McCormick Aug 26 '20 at 15:03

There are easier ways to enhance Mars's atmospheric pressure, so no, don't use Venus materials. I calculated the energy required to lift a kg of nitrogen — or a kg of anything, for that matter — out of Venus's gravity well, and uphill through the sun's gravity well to Mars. Getting it away from Venus was a small part of the total, but that total was nearly 700 MegaJoules, far more than chemically reacting 1 kg of anything could supply. Lugging stuff up the solar gravity well isn't easy!

But there are other ways. For example, there are many objects flying around in the solar system that contain huge amounts of volatiles, such as comets and some asteroids, and some of those are in orbits that are not as difficult to divert to Mars as lugging up from Venus. The savings in energy is greater than the energy needed to make N2 from the NH3 in, say, a comet.

That said, the amount of energy needed for this undertaking currently is far beyond what we can muster.

So no, for multiple reasons Venus shouldn't worry about somebody swiping its nitrogen!

  • $\begingroup$ My thoughts were if we were going to Terraform mars we might also want to terraform venus as well. These are mega-engineering projects and we would need to do something with Venus's atmosphere anyway. $\endgroup$ – Tracy McCormick Aug 26 '20 at 15:08
  • $\begingroup$ The mass of CO2 in Venus's atmosphere is only about double the mass of CO2 locked up in carbonate rocks on Earth. With cooling of the atmosphere (not an easy task!) & the addition of Ca & Mg, we could precipitate the CO2 as limestone and dolomite. There might be enough Ca and Mg in Venus's crust to suffice, otherwise you need to bring in asteroids of the right type. Once you have the limestone and dolomite you use it to build pretentious government buildings, temples, and the like. ;-) $\endgroup$ – Tom Spilker Aug 26 '20 at 23:40

No. Moving N2 or O2 wouldn't make sense, because it would require moving about a quadrillion tons from one planet to another, while we've barely figured out how to move one ton up from one gravity well and down into another.

Once we can do that kind of engineering (pick a favorite technology from science fiction), we may have already become bored with terraforming.

  • $\begingroup$ Yea my thought is by the time we would want to do something like this we would have a lot of automation. Most likely if we wanted to terraform Mars we might also want to work on terraforming venus as well. I'm sure either project would take a lot of time and tech we haven't dreamed up except in Science Fiction. $\endgroup$ – Tracy McCormick Aug 26 '20 at 15:19

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