No, we can't. But we can go one step better - that is if there was any reason to do it. There are enough resources in the asteroid belt to build habitats spinning to create artificial gravity with 1000 times the surface area of the Earth. This is a calculation that goes back to the 1970s when they started to explore ideas of O'Neil cylinders, Stanford Torus habitats etc.
That's just the "ground floor" - the calculation is based on the amount of material available for cosmic radiation shielding, at 4.5 tons per square meter, which is the limiting factor. You build your houses etc on top of that and in some suggestions you have multiple habitation layers on top of that basic structure.
So - if we wanted to, if we had the motiviation, we could create - not entire planets but the surfaces of entire planets
For instance - we could recreate the entire surface of Mars with Mars gravity in space. And several Earths if we want. And simulate similarly any exoplanet we like. If we get to the point where this is easy to do - e.g. with 3D printers and Von Neumann machines - we can pretty much can create as many planetary surfaces as we like for the foreseeable future, within our solar system, with just about any desired gravity levels, atmosphere conditions etc.
Not as one big habitat. But lots of smaller habitats with total surface area the same as that of a thousand Earths. Each one maybe a few tens or hundreds or thousands of square kilometers of living area. Eventually even larger ones.
One limitation - we can't create oceans for them all, not like the Earth's oceans. We can have "water world" type stanford torus habitats yes. But not as big in volume as the Earth's seas, not from materials in the asteroid belt.
Also - that's assuming you don't need to have the multiple kilometers thickness of the Earth's atmosphere. If we do - that ten tons per square meter of atmosphere amounts to a major part of the station's mass. But seems no reason why we can't make do with a thinner layer of atmosphere a few hundred meters in depth, held in by the structure of the space station.
Really - why bother with the interior of the planets? Nobody lives anywhere except on the surface of the Earth.
This though is assuming some major future technology shift. Maybe with Von Neumann machines so that it becomes as easy to build a rotating Stanford Torus type space station as it is to build a house on the Earth.
That might not be more than a few decades away.
Also - those limitations on oceans and atmosphere are the result of using materials from the asteroid belt, which have fewer volatiles than the comets further out. We could build entire oceans and also atmospheres as thick as Earth's from resources in the Oort cloud and Kuiper belt if we want.
Once we can use resources out there, then we can do just about anything by way of planetary surface creations.
Whether we should do it is another matter. Personally though I like the idea, I'm not sure that humans are quite mature enough yet to start to spread out into space like this. And perhaps once we are mature enough we might do it with some caution. Spreading throughout the galaxy would be a likely next step - but what would a galaxy full of humans be like? Not us - but descendants of us - with unimaginable powers able to reshape planets and stars most likely - and with the capability to build cyborgs and artificial lifeforms, and who knows what else - they wouldn't necessarily have the same motivations and approaches that we do.
After all there are plenty of humans that cause problems for others on Earth just due to differing ideologies. Now imagine that it's an entire galaxy of humans - but many are not even quite human - and some are self replicating machines created by humans - and some are part human part machine - and some of them are
Would it be a wonderful, peaceful, Star trek like universe? Or would it be a nightmare, galaxy filled with alien species descended from humans that would invade the Earth multiple times (or whatever place you end up)?
And is not a good reason to do it because we want to be first. What is so good about humans being the first to do this? Maybe the reason there are no ETs here is because any sensible ETs contemplate this possible future and decide, that colonizing the galaxy is not the best thing to do quite yet. And maybe they are right. Or the ones that do colonize it - do it in such a careful way that that is why they are so sparse on the ground and we dont' see any in our solar system.
I think quite possibly ETs that just rush out and colonize as quickly as they can probably don't last long and probably don't get as far as colonizing their own solar system even before they destroy themselves or at least put themselves back to a pre-space age level of technology with wars in space.
So - I think there is more to this than meets the eye and we do well to step slowly to start with and explore first, and find out more first. And I think though it is a bit of a shame in some ways, we might be lucky that it is actually quite hard to build these planets.
But when the time comes - if we decide to do it - we can easily build the surfaces of a thousand planets. And with resources from the Oort cloud and Kuiper belt - their oceans too.
Asteroid Resources Could Create Space Habs For Trillions; Land Area Of A Thousand Earths
That's just the "ground floor" - the calculation is based on the amount of material available for cosmic radiation shielding, at 4.5 tons per square meter, which is the limiting factor. You build your houses etc on top of that and in some suggestions you have multiple habitation layers on top of that basic structure.
So - if we wanted to, if we had the motiviation, we could create - not entire planets but the surfaces of entire planets
For instance - we could recreate the entire surface of Mars with Mars gravity in space. And several Earths if we want. And simulate similarly any exoplanet we like. If we get to the point where this is easy to do - e.g. with 3D printers and Von Neumann machines - we can pretty much can create as many planetary surfaces as we like for the foreseeable future, within our solar system, with just about any desired gravity levels, atmosphere conditions etc.
Not as one big habitat. But lots of smaller habitats with total surface area the same as that of a thousand Earths. Each one maybe a few tens or hundreds or thousands of square kilometers of living area. Eventually even larger ones.
One limitation - we can't create oceans for them all, not like the Earth's oceans. We can have "water world" type stanford torus habitats yes. But not as big in volume as the Earth's seas, not from materials in the asteroid belt.
Also - that's assuming you don't need to have the multiple kilometers thickness of the Earth's atmosphere. If we do - that ten tons per square meter of atmosphere amounts to a major part of the station's mass. But seems no reason why we can't make do with a thinner layer of atmosphere a few hundred meters in depth, held in by the structure of the space station.
Really - why bother with the interior of the planets? Nobody lives anywhere except on the surface of the Earth.
This though is assuming some major future technology shift. Maybe with Von Neumann machines so that it becomes as easy to build a rotating Stanford Torus type space station as it is to build a house on the Earth.
That might not be more than a few decades away.
Also - those limitations on oceans and atmosphere are the result of using materials from the asteroid belt, which have fewer volatiles than the comets further out. We could build entire oceans and also atmospheres as thick as Earth's from resources in the Oort cloud and Kuiper belt if we want.
Once we can use resources out there, then we can do just about anything by way of planetary surface creations.
Whether we should do it is another matter. Personally though I like the idea, I'm not sure that humans are quite mature enough yet to start to spread out into space like this. And perhaps once we are mature enough we might do it with some caution. Spreading throughout the galaxy would be a likely next step - but what would a galaxy full of humans be like? Not us - but descendants of us - with unimaginable powers able to reshape planets and stars most likely - and with the capability to build cyborgs and artificial lifeforms, and who knows what else - they wouldn't necessarily have the same motivations and approaches that we do.
After all there are plenty of humans that cause problems for others on Earth just due to differing ideologies. Now imagine that it's an entire galaxy of humans - but many are not even quite human - and some are self replicating machines created by humans - and some are part human part machine - and some of them are
Would it be a wonderful, peaceful, Star trek like universe? Or would it be a nightmare, galaxy filled with alien species descended from humans that would invade the Earth multiple times (or whatever place you end up)?
And is not a good reason to do it because we want to be first. What is so good about humans being the first to do this? Maybe the reason there are no ETs here is because any sensible ETs contemplate this possible future and decide, that colonizing the galaxy is not the best thing to do quite yet. And maybe they are right. Or the ones that do colonize it - do it in such a careful way that that is why they are so sparse on the ground and we dont' see any in our solar system.
I think quite possibly ETs that just rush out and colonize as quickly as they can probably don't last long and probably don't get as far as colonizing their own solar system even before they destroy themselves or at least put themselves back to a pre-space age level of technology with wars in space.
So - I think there is more to this than meets the eye and we do well to step slowly to start with and explore first, and find out more first. And I think though it is a bit of a shame in some ways, we might be lucky that it is actually quite hard to build these planets.
But when the time comes - if we decide to do it - we can easily build the surfaces of a thousand planets. And with resources from the Oort cloud and Kuiper belt - their oceans too.
Asteroid Resources Could Create Space Habs For Trillions; Land Area Of A Thousand Earths
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
4.8m answer views110.4k this month
Top Writer2017, 2016, and 2015
Published WriterHuffPost, Slate, and 4 moreHuffPost, Slate, Forbes, Newsweek, Business Insider, and Science 2.0