The Bad Astronomer Talks Asteroids

Article written: 13 Oct , 2011
Updated: 14 Jan , 2016
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Here’s a great talk given by our friend Phil Plait at a TED event, TEDxBoulder, about how an asteroid might one day give us Earthlings a really bad day. But he’s got good news, too: We have a space program!

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5 Responses

  1. I like the idea of capturing asteroids, especially metal rich asteroids. We not only become rich in doing so, we lower the costs of everything made of those metals because the supplies will be that much more abundant. And the environmental and social stresses of things like open pit and other types of mining will be reduced as those enterprises become less economical.

    • squidgeny says

      Mining an asteroid is going to be a tremendously expensive endeavour, regardless of how abundant they are.

      First, we’d need to bring the asteroid down to the Earth’s surface, because the processes of extracting, refining and shaping the metals require an environment with gravity and atmospheric pressure. Building a refinery in space that would simulate this environment (and be capable of equipping the necessary furnaces) would be horrifically expensive, if not outright technically impossible.

      Gently ferrying the asteroids down to the Earth’s surface in re-entry capsules isn’t going to be feasible, because the ‘everyday’ re-entry capsules we have won’t be able to take the size (unless we carefully splinter the asteroid, which itself is a technical challenge) or the weight of the lumps of rock. We would have to design and build new, heavy-duty re-entry capsules, which represents a huge investment.

      That investment is not going to be worth it, so the solution is just to throw the asteroid into the Earth and pick up the peices later. Easy enough, we’ve done it for satellites – but we normally throw those into the middle of the Pacific to reduce risk. We couldn’t do that with an asteroid because it would just sink to irretreivable depths. Obviously we can’t endanger lives so any habitable areas are out. That leaves the deserts and the icecaps. Smack an asteroid into those, and we’d still have a significant challenge in finding the damn thing and collecting the bits for processing. And we’d still need the space-infrastructure for safely steering an asteroid into the right trajectory.

      Creating the infrastructure for all this will only be economical if we harness asteroids in droves, but asteroids don’t just waltz over to Earth on their own accord – we’d have to grab them out of their existing orbits, which represents the biggest technical challenge of all. Rockets, space ships and huge amounts of fuel would be needed.

      It’ll be far, far cheaper to strip-mine metals from the Earth (or just recycle and re-use the metals we’ve already extracted) and probably will be forever and ever.

      • You seem to be making the assumption that once the asteroid is captured in Earth orbit mining it will be the only orbital activity. That other industrial processes will be done on the surface of the Earth. Instead think of it as the seed for the industrialization of space.

        Space also has abundant amounts of solar power available close to 24/7 – without clouds or night to interfere. It was recently discovered that anti-matter is being captured in the Earth’s magnetic field. SEPs (Solar Energetic Particles) are available. Volatiles may be found in the asteroid, itself. Or they could be found in/on the Moon

        Manufacturing techniques can be adapted or invented for micro-gravity. Re-entry capsules could be manufactured from what is mined from the asteroid, itself. Automation, AI, nanotechnology and robotics are making tremendous strides. These can and will be used in space.

        And to say it is not worth the investment is an opinion that may or may not be true. To think only in terms of current technology, current political and economic conditions is short sighted. Things change. Disruptive technologies happen. Visionary entrepreneurs do arise.

        Luddite arguments and impatience not withstanding, there will be progress made in the exploitation of non-terrestrial environs. Over the long term, the advantages of space will be exploited.

    • squidgeny says

      Mining an asteroid is going to be a tremendously expensive endeavour, regardless of how abundant they are.

      First, we’d need to bring the asteroid down to the Earth’s surface, because the processes of extracting, refining and shaping the metals require an environment with gravity and atmospheric pressure. Building a refinery in space that would simulate this environment (and be capable of equipping the necessary furnaces) would be horrifically expensive, if not outright technically impossible.

      Gently ferrying the asteroids down to the Earth’s surface in re-entry capsules isn’t going to be feasible, because the ‘everyday’ re-entry capsules we have won’t be able to take the size (unless we carefully splinter the asteroid, which itself is a technical challenge) or the weight of the lumps of rock. We would have to design and build new, heavy-duty re-entry capsules, which represents a huge investment.

      That investment is not going to be worth it, so the solution is just to throw the asteroid into the Earth and pick up the peices later. Easy enough, we’ve done it for satellites – but we normally throw those into the middle of the Pacific to reduce risk. We couldn’t do that with an asteroid because it would just sink to irretreivable depths. Obviously we can’t endanger lives so any habitable areas are out. That leaves the deserts and the icecaps. Smack an asteroid into those, and we’d still have a significant challenge in finding the damn thing and collecting the bits for processing. And we’d still need the space-infrastructure for safely steering an asteroid into the right trajectory.

      Creating the infrastructure for all this will only be economical if we harness asteroids in droves, but asteroids don’t just waltz over to Earth on their own accord – we’d have to grab them out of their existing orbits, which represents the biggest technical challenge of all. Rockets, space ships and huge amounts of fuel would be needed.

      It’ll be far, far cheaper to strip-mine metals from the Earth (or just recycle and re-use the metals we’ve already extracted) and probably will be forever and ever.

    • Member
      Anonymous says

      I too like the idea of mining asteroids, but first it would be good to see if it’s worth the effort? Those asteroids determined to have high metal(s) content – not just any metals – might be useful for on-orbit fabrication purposes? Whereas water rich asteroids might be used for fuel and/or electrolyzed oxygen content?

      How to bring those masses closer to Earth or safer lunar orbits is an interesting problem. Mass tractors a possibly? Robotic assemblage of solar sails? Or perhaps using lasers or masers to create thrust on a chosen asteroid by sequentially ablating surface areas? The trick would be to use Jupiter, Mars and/or the Moon’s gravity wells to shape the desired orbitals. THEN getting to them with the right tools…

      I also like the idea of fabricating re-entry vehicles from the mined material to bring those rarer and more profitable materials down to earth’s surface.

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