I want to partially terraform Venus, enough to make it feasible to mine minerals etc,. there. To do this I need to do a few things but for this question I'm focusing on stripping away at least some of the atmosphere either by design or by fortuitous accident.

Would a large asteroid or manmade object passing close to Venus' atmosphere on a one way trip to the Sun, made of a very dense material I just made up which is 100 times the density of Osmium be able to pull some or most of the atmosphere away from Venus. How big would it need to be, and how fast relative to Venus would it need to be moving? I don't want it pulling Venus out of orbit into the Sun as well.

Am I even correct in assuming a dense material has that sort of gravity power?

  • $\begingroup$ An asteroid will not work, no matter of the material, because it will pull not only the atmosphere and it should pull atmosphere from opposite side too. Why not focus on the manmade objects, an orbital ring is pretty suitable for that kind of thing. Also, strip mining is possible without removing the atmosphere. Those 2 directions are viable in the realm of physics and such. $\endgroup$
    – MolbOrg
    Commented Apr 17, 2017 at 10:40
  • $\begingroup$ @MolbOrg Strip mining is possible? They can't even land a drone on the surface and have it survive, I want factories down there. So I need that enormous pressure and more importantly the heat cut down to size. $\endgroup$
    – Kilisi
    Commented Apr 17, 2017 at 10:41
  • $\begingroup$ @Killsi again that is not a problem that they can't land yet, and getting new knowledge is the point of asking questions right? You can have a city there(it might be tricky and not necessary - floating stuff have great perspectives). But I said removing atmosphere is possible too. $\endgroup$
    – MolbOrg
    Commented Apr 17, 2017 at 10:44
  • $\begingroup$ Good, this question is about removing the atmosphere or at least some of it. I want people on the surface. $\endgroup$
    – Kilisi
    Commented Apr 17, 2017 at 10:47
  • $\begingroup$ I recommend then to edit the question accordingly, and focus more on the things you would like to have, to allow the reader to understand your needs. $\endgroup$
    – MolbOrg
    Commented Apr 17, 2017 at 10:51

1 Answer 1


Your proposal is based on an intuitive conceptualization. Basically it won't work. Any object with sufficient gravitation to pull a planet's atmosphere away, will be powerful enough to pull the planet out of its orbit.

Also, it is unlikely to require a single pass to strip the atmosphere. That would require an extremely massive object, possibly with a mass the order of a planet, and that would undoubtedly deflect Venus from its orbit.

To make something like this to even approximately work you would need two equally massive objects to counteract each other's gravitational deflection. of course, that might counteract their ability to remove the Venusian atmosphere.

The simple answer is using dense objects to strip the atmosphere of Venus won't work by gravitation alone. There are simply too many problems. Simple stuff like how do make hyperdense objects with great mass move and move in the right way to remove an atmosphere (even if that was possible).

Lifting the mass of an extremely dense atmosphere out of its planet's gravitational well requires colossal amounts of energy. So does moving dense objects.

So it's back to the drawing board and devise another way of removing the atmosphere of the plant Venus.

  • $\begingroup$ Massive is fine, because I'm concentrating the mass into a much smaller volume, but it doesn't have to take the whole atmosphere, just some of it. But I see what you mean. Possibly I need a different shape to my object rather than a lump or sphere. I'm not going to introduce more issues about moving the object, just assuming I can do whatever I want with it at this stage. Looks like an asteroid is definitely a no go though. $\endgroup$
    – Kilisi
    Commented Apr 17, 2017 at 12:16
  • $\begingroup$ @Kilisi You seem to be trying for a solution with mostly ordinary physics. That is nigh on impossible using massive objects to remove the Venusian atmosphere without causing lots of additional problems, The alternative would be to use exotic and highly speculative science. I thought about Robert Forward's ultradense matter concept (effectively neutron star densities), but that is still very tricky (this means most likely unworkable and with lots of problems). Good luck with other answers. Someone else might have better ideas. $\endgroup$
    – a4android
    Commented Apr 18, 2017 at 2:08
  • $\begingroup$ I'm thinking of Hydrodynamic escape and Chthonian planet, but I don't exactly understand how it work. $\endgroup$
    – Vylix
    Commented Apr 18, 2017 at 2:11
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    $\begingroup$ @Kilisi You might to look at this answer. It has alternative methods rendering Venus habitable. worldbuilding.stackexchange.com/questions/14050/… $\endgroup$
    – a4android
    Commented Apr 18, 2017 at 2:14
  • $\begingroup$ @a4android yes I read that link a few times without being convinced.of anything $\endgroup$
    – Kilisi
    Commented Apr 18, 2017 at 5:10

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