Mercury is also much denser than Mars - it's quite a lot smaller, but has about the same surface gravity. And again, mass doesn't make a magnetic field. For that you need the iron core to be spinning in a molten outer core, which Mars doesn't have and we wouldn't have the first clue about how to change that, but dropping rocks on the planet isn't the answer. (Venus doesn't have one either.)
And no, water doesn't take up excess sulfur - or rather, when it does you get sulfuric acid, which is what Venus' clouds are mostly made of. Venus doesn't have a problem with carbon dioxide, it has a problem with sulfur dioxide.
the problem is size. It'd have to be as big as Ceres.... And Ceres is more rock than metal... never mind the difficulty of moving an object of that size.... actually you might be better off just using Mercury....
would it not be possible to actually slam an iron rich asteroid into Mars? angle it so it eventually sinks into the core? Iron or nickel.
My guess is there would large debris ejected into space sent into a solar orbit that could hit us. And Mars' own orbit could change. Not to mention how offended the Martians would be.
That's a negative on "eventually sinking into the core", unless you're willing to wait several aeons for the job to be finished. And even then, you'll need a pretty large mass of metals - Ceres won't do the job, it turns out to be largely ice and besides I doubt there's enough mass there. See, the thing is, Mars is solid, and solids generally don't slide through each other all that well, hence my ability to sit on this chair even though I outmass it by a solid sixty or seventy kilos. If you plowed an iron-rich asteroid into the planet at cometary velocity, you'd make a pretty doggone impressive crater, and some of the ejecta might even eventually fall to Earth (it's happened in the past), but that's a no-go on restarting any significant degree of volcanism.
(Besides, the planet's already pretty rich in iron, hence the surface coloration. It's just that the average density of the planet is so low, and barring mass transmutation that's not changing any time soon. And if you have mass transmutation, who needs planets?)
Yeah I've thought of tossing Mercury at Mars. It would solve the problem, but then we wouldn't be able to mine Mercury. But could we toss Mercury at Venus and put it in orbit?
I'd rather keep Mercury right where it is, thanks - no point colliding planets, only to TRIBBLE up the orbital mechanics of the rest of the Solar system and maybe ruin the one planet we already have.
If we ever had access to such extreme measures of energy in terms of delta V, and there is no overerstating how much energy is involved in moving planets, it's at truly mind boggling astronomical amounts, it would be far FAR easier for us at that point to just send ourselves to other nearby potentially more favorable exo-planets yet to be discovered at relativistic velocities. Also, to ever try to collide an inner planet such as Mercury into Mars would mean you'd have to send it for at least a time across Earths orbit, and that means you'd better send it flying past pretty darn fast when Earth is at it's farthest point away to avoid the possibility of the gravity of the two planets from interacting too strongly, causing nasty orbit changes to Earth and tidal effects (plus the delicate Earth and Moon tidal harmony). So then you'd need even more insanely astronomical amounts of energy for that kind of delta V.
It might also be easier and cheaper in terms of delta V cost to steal an outer moon or two from a gas planet in outer solar system, but I could be wrong without doing the math of certain candidate moons (They best be as far away from their host planet as possible so you don't need as much delta V to pull them away). But again at that point, it makes little sense to use such amounts of energy wastefully like that.
For the far future, most of my bets are on exo-planets, or possibly floating atmospheric colonies in outer gas planets for the possibility of more reasonable gravity and protection.
There's also the fact that each planet's orbit affects the others in the "nearby" parts of the Solar System - you could remove, say, Pluto or Eris with little ill effect, but removing Mercury from its orbit will result in gravitational interactions with the orbit of Venus, which could be extremely bad news for Earth...
The energies involved are, as Kitsune points out, also sufficiently horrific that using near-lightspeed relativistic drives to cross interstellar space would probably be cheaper and easier. Then, if you don't find an Earthlike world in another system, you can start cosmo-engineering that system, assuming it has no sophonts to object, and not risk the species' homeworld if you make a mistake.
I think any technological stage where we start moving planets around to increase the mass or add an iron core to Mars would be after a stage where we can colonize Mars. Building a large transparent dome on Mars with a biosphere inside seems a lot more plausible then trying to move planets in any human-relevant time scales.
It is almost sounding from this overall discussion like we as a species are going to have the resources to push an O'Neill cylinder out to a relatively friendly exoplanet (think along the lines of Project Orion) and attempt to settle/colonize THAT, well before we have what it takes to bring Mars up to truly habitable standards or even make a sheltered colony sustainable there.
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It is almost sounding from this overall discussion like we as a species are going to have the resources to push an O'Neill cylinder out to a relatively friendly exoplanet (think along the lines of Project Orion) and attempt to settle/colonize THAT, well before we have what it takes to bring Mars up to truly habitable standards or even make a sheltered colony sustainable there.
The way I see it - any forms of "terraforming" Mars attempting to make a huge atmosphere, jump-start a magnetic field by adding lots of iron to the planet, or adding mass to it, is pretty much a pipe dream. But also not really necessary for colony. I am not sure if we can make it self-sustainable, admittedly. Maybe we can. A planet's gravity can make some things inconvenient for space exploration, but the colonization of Mars is not space exploration in that regard. You're happy if things stuck to your chosen home, you can maintain a (even if on geologically time scales only for a short time) an atmosphere for a while without technological help. And you got a large object containing plenty of raw materials that might be of use. We might need a lot of supplies first to become self-sustainable, but help is just a few weeks or months away.
In contrast, a long term exploration vehicle with a self-sustaining environment seems a lot more difficult. Without fairy dust, negative energy or similar exotic materials, it looks to be a slow ride (far) below the speed of light that might take centuries or millenias.
Humanity has yet to build something that can last that long without deteriorating significantly, even less something that could be considered self-sustainable. Heck, I think we haven't even had nations last as long as required...
We can't just import goods from elsewhere, we have to bring all the items and raw materials we are going to need with us. Maybe we can take a few stops along the way, but we're probably still talking years between those. Space is mostly empty. Well, empty in one sense - there is no shortage of stuff that could kill the crew.
Seriously, interstellar exploration of range looks really sad at the moment*. And it's not like our technology hasn't made crazy advancements in the past century. Or 20 years...
My first computer had a 40 MB Hard Disk. A few years ago I got an 8 MB USB Stick, that was what - 1/100th of the size. And last week I got a 64 GB USB Stick that seems to mostly consist out of the USB adapter and an LED - I have no idea where the damn memory is supposed to be stored.
But other technology has not advanced so fast - we don't have car-installed nuclear fission or fusion reactors, our passenger jets don't fly faster than the speed of sound, and we are just now trying to build reusable space craft again, after we have given on our first attempt.
*) And holy fracking sh*t - this universe is incredibly, mind-numbing big. No one has a real sense of how big it is, or at least not me, but even the vague idea of it is still incredible. There are giant intergalactic structures that we'll never be able to visit with our current understanding of the inherent limitations of travel. Even in Star Trek, Stargate or Star Wars FTL capabilities, the universe is still incredibly mind-numbing big and contains spots that seem practically unreachable.
Admittedly, being there might actually be pretty unspectacular - once you've seen a billion of galaxies, it probably gets old. But still, the egocentric or antrophocentric part of me asks- why so big? We can practically see or use nothing of that! WTF, Universe? Are you messing with us?
Star Trek Online Advancement: You start with lowbie gear, you end with Lobi gear.
*) And holy fracking sh*t - this universe is incredibly, mind-numbing big. No one has a real sense of how big it is, or at least not me, but even the vague idea of it is still incredible.
"The Hitchhiker's Guide to the Galaxy has this to say on the subject of space. 'Space,' it says, 'is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. Listen...'"
On the plus side, for energies far less than those involved in moving planets one can easily achieve relativistic velocities, such that travel to another star is easily within the lifespan of the travelers (thanks to the phenomenon of time dilation). Of course, the downside there is that we have yet to discover a star system with any worlds even vaguely approaching Earth - the closest we've found would have a surface gravity of around 1.5g and probably be tidally locked to its star - but then we're only just developing the technologies necessary to see such a world at more than a few lightyears' distance...
I agree with the idea of using domes. Terraforming an entire planet is going to take dozens of human lifetimes, whereas we can dome-in whatever we need in a relatively shorter time span. In fact, other than our psychological need to see the open sky, we may as well build our actual cities underground and use the domes only for parkland and agriculture.
It is almost sounding from this overall discussion like we as a species are going to have the resources to push an O'Neill cylinder out to a relatively friendly exoplanet (think along the lines of Project Orion) and attempt to settle/colonize THAT, well before we have what it takes to bring Mars up to truly habitable standards or even make a sheltered colony sustainable there.
An O'Neill cylinder with fusion engines on it is a pretty good starting point for a generation ship--you've got a whole ecosphere that ought to be self-sustaining for centuries as long as you have enough fuel to power your reactors, plus it gives you a decent place to live while you build more cylinders (or terraform) in your destination system, plus it gives you a good place to keep all of your biological samples in situ rather than on ice.
In a pinch we could always do like Project Orion and detonate a bunch of nukes to accelerate up to speed, and then use a solar sail to slow down as we come into the target system...though IF fusion could be made practical that would be the better bet.
Christian Gaming Community Fleets--Faith, Fun, and Fellowship! See the website and PM for more. :-) Proudly F2P.Signature image by gulberat. Avatar image by balsavor.deviantart.com.
I think any technological stage where we start moving planets around to increase the mass or add an iron core to Mars would be after a stage where we can colonize Mars. Building a large transparent dome on Mars with a biosphere inside seems a lot more plausible then trying to move planets in any human-relevant time scales.
Going back for a minute to a level of science I feel fairly sure about :
Light is also radiation; at first guess you'd expect that a dome that was transparent to light would also be transparent to other and nastier forms of radiation.
Do we currently have materials that are properly transparent to visible light but are opaque to the various dangerous stuff that the Earth's atmosphere and magnetic field normally keep out?
I know ordinary glass is less transparent to infra-red than to visible light (hence why greenhouses heat up: light goes in, is absorbed by the soil and the floor and the energy heats them up, but the heat the warm surfaces radiate doesn't go straight out again because that's infra-red radiation). Checking Wikipedia, ordinary glass is also less transparent to ultraviolet A and completely opaque to the shorter wavelength (i.e. nastier) ultraviolet B and C. (That might actually be a problem to Mars colonists, as ultraviolet B is the part of sunlight that's needed to produce vitamin D - either this would have to be got round or they'd have to rely completely on taking synthetic vitamin D.) I don't know about other wavelengths, off-hand.
My first computer had a 40 MB Hard Disk. A few years ago I got an 8 MB USB Stick, that was what - 1/100th of the size. And last week I got a 64 GB USB Stick that seems to mostly consist out of the USB adapter and an LED - I have no idea where the damn memory is supposed to be stored.
But other technology has not advanced so fast - we don't have car-installed nuclear fission or fusion reactors, our passenger jets don't fly faster than the speed of sound, and we are just now trying to build reusable space craft again, after we have given on our first attempt.
USB sticks use a microchip about the same size as the LED for data storage.
Mini-fission reactors small enough to fit in cars have actually been designed, BUT highway safety laws prohibit their use. Something about the danger of radioactive fallout if you wreck....
*points at Concorde* But it was expensive, and may or may not have actually been practical.
And yeah, the US space shuttle program.... was not a viable long term solution. There were a lot of things that really weren't reusable, most importantly the external boosters and heat shield.
In a pinch we could always do like Project Orion and detonate a bunch of nukes to accelerate up to speed, and then use a solar sail to slow down as we come into the target system...though IF fusion could be made practical that would be the better bet.
From what I've been hearing, fusion seems to be finally getting there. Their estimates of when it'll be ready seem to have stopped changing! If I remember rightly, they have got to the point of getting an experimental setup to generate more energy than they needed to put in; they're now building a very big prototype in France.
*) And holy fracking sh*t - this universe is incredibly, mind-numbing big. No one has a real sense of how big it is, or at least not me, but even the vague idea of it is still incredible.
"The Hitchhiker's Guide to the Galaxy has this to say on the subject of space. 'Space,' it says, 'is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. Listen...'"
Yeah, I had to think of that passage, too. I think Douglas Adams might have had entered the same mindset as I did when I wrote my post. (And probably, just as me, had thought about it a few times before like that... )
On the plus side, for energies far less than those involved in moving planets one can easily achieve relativistic velocities, such that travel to another star is easily within the lifespan of the travelers (thanks to the phenomenon of time dilation). Of course, the downside there is that we have yet to discover a star system with any worlds even vaguely approaching Earth - the closest we've found would have a surface gravity of around 1.5g and probably be tidally locked to its star - but then we're only just developing the technologies necessary to see such a world at more than a few lightyears' distance...
Even if it's "far less", it's still actually a lot, and it's still a possibly insurmountable challenge. If you actually want to benefit from relatistic effects, you need a decent acceleration ,but you can't accelerate much faster than 1g if you want to have humans aboard, and you need to maintain that acceleration for a long time - possibly year. And you need a lot of fuel, to transport yourself and all the fuel you need to transport yourself and all the fuel ...
And once you reach relativistic speed, the vast nothingness of space suddenly is not empty enough anymore, and you have to deal with dangerous particle collisions or high energetic radiation.
The challenges that lie ahead are incredible.
Star Trek Online Advancement: You start with lowbie gear, you end with Lobi gear.
In a pinch we could always do like Project Orion and detonate a bunch of nukes to accelerate up to speed, and then use a solar sail to slow down as we come into the target system...though IF fusion could be made practical that would be the better bet.
How much nuclear material do you actually need for that?
How do you build something that survives those nuclear blasts as often as needed, and will still do it years, decades or centuries later when you arrive in the target system? A solar sail won't slow you down as fast as those nuclear blasts.
An O'Neill cylinder with fusion engines on it is a pretty good starting point for a generation ship--you've got a whole ecosphere that ought to be self-sustaining for centuries as long as you have enough fuel to power your reactors, plus it gives you a decent place to live while you build more cylinders (or terraform) in your destination system, plus it gives you a good place to keep all of your biological samples in situ rather than on ice.
The "O'Neill" cylinder is just the name of a hypothetical construct - there isn't yet a construction plan for it.
If we could build this, it would probably be a good idea, but actually suddenly a lot less urgent - if Earth seems to become uninhatbile, the tech required for the cylinder could also be applied on an Earth project. (Even if we can't cover the whole Earth). Only extreme huge asteroid crashes (or small ones that will hit the cylinder directly) and the Sun's demise would still pose concerns. (Even if we have a self-sustaining ecosphere, we probably can't maintain it inside the sun.)
I think any technological stage where we start moving planets around to increase the mass or add an iron core to Mars would be after a stage where we can colonize Mars. Building a large transparent dome on Mars with a biosphere inside seems a lot more plausible then trying to move planets in any human-relevant time scales.
Going back for a minute to a level of science I feel fairly sure about :
Light is also radiation; at first guess you'd expect that a dome that was transparent to light would also be transparent to other and nastier forms of radiation.
Do we currently have materials that are properly transparent to visible light but are opaque to the various dangerous stuff that the Earth's atmosphere and magnetic field normally keep out?
I know ordinary glass is less transparent to infra-red than to visible light (hence why greenhouses heat up: light goes in, is absorbed by the soil and the floor and the energy heats them up, but the heat the warm surfaces radiate doesn't go straight out again because that's infra-red radiation). Checking Wikipedia, ordinary glass is also less transparent to ultraviolet A and completely opaque to the shorter wavelength (i.e. nastier) ultraviolet B and C. (That might actually be a problem to Mars colonists, as ultraviolet B is the part of sunlight that's needed to produce vitamin D - either this would have to be got round or they'd have to rely completely on taking synthetic vitamin D.) I don't know about other wavelengths, off-hand.
Yes, that's an interesting aspect. We could probably build a dome that could protect us from some or all forms of ration, but maybe we'd cover more than we want? I am not sure what wave lengths plants use for their photosynthesis. (I read a while ago there are actaully two forms of photosynthesis, some plant species use the one, other plants use the other one. But I don't remember what wavelength they used.)
An alternate take is that the dome (if we have them all, this is just one popular concept, but how good is it really?) is just for agriculture - we'd still go with radiation suites outside there, and stay otherwise inside buildings or underground.
If we even need full suites - it depends on how quickly the radiation becomes an actual concern, maybe we'd need just some heavier clothing, or maybe we can just stay unprotected entirely for a few hours each day. Maybe we don't even go out during the day.
Star Trek Online Advancement: You start with lowbie gear, you end with Lobi gear.
Yeah we really only need the surface for photosynthesis, solar power, and the psychological effect of being in a large, open green space, so we may as well keep the rest of the city underground except for venting excess heat, etc.
well, there has to be an artificial way of establishing a magnetic shield.
Toss some ice at the surface, specifically on one side, so we got the other side of the planet for mining for a few years at least. There's your atmosphere. Use some tech to establish a magnetic shield and people can walk the surface. I'd probably keep the cities shielded though.
Atmospheres are a tad more complicated than that, and if there's some way to artificially generate a geomagnetic field, we don't know what it is yet. What's wrong with enclosed colonies, anyway?
Enclosed colonies are fine from a practical standpoint. It's just that there is a huge romantic attraction about having a world where we can walk about in the open and have wildlife roam like on Earth, and without warp drive we will have to make our own new habitable world, since any that might exist are trillions of miles away.
Getting venereal disease from the sun??? Vitamin D, on the other hand, can be supplemented the same way as any other missing vitamin.
I just yesterday learned something very interesting about areography. The northern hemisphere of Mars is markedly smoother than the southern, and apparently averages one kilometer lower in altitude. It's hypothesized that this may be due to a collision with something about the size of Earth's Moon - which also stripped away much of the atmosphere during the collision.
So crashing Ceres into Mars might in fact do exactly the opposite of what you hoped...
Comments
And no, water doesn't take up excess sulfur - or rather, when it does you get sulfuric acid, which is what Venus' clouds are mostly made of. Venus doesn't have a problem with carbon dioxide, it has a problem with sulfur dioxide.
I understand that so2 is the problem with Venus, I do. The question I pose is; what stopped Earth from having this problem when our supers blow?
My character Tsin'xing
My guess is there would large debris ejected into space sent into a solar orbit that could hit us. And Mars' own orbit could change. Not to mention how offended the Martians would be.
(Besides, the planet's already pretty rich in iron, hence the surface coloration. It's just that the average density of the planet is so low, and barring mass transmutation that's not changing any time soon. And if you have mass transmutation, who needs planets?)
My character Tsin'xing
It might also be easier and cheaper in terms of delta V cost to steal an outer moon or two from a gas planet in outer solar system, but I could be wrong without doing the math of certain candidate moons (They best be as far away from their host planet as possible so you don't need as much delta V to pull them away). But again at that point, it makes little sense to use such amounts of energy wastefully like that.
For the far future, most of my bets are on exo-planets, or possibly floating atmospheric colonies in outer gas planets for the possibility of more reasonable gravity and protection.
The energies involved are, as Kitsune points out, also sufficiently horrific that using near-lightspeed relativistic drives to cross interstellar space would probably be cheaper and easier. Then, if you don't find an Earthlike world in another system, you can start cosmo-engineering that system, assuming it has no sophonts to object, and not risk the species' homeworld if you make a mistake.
Just a note: Mercury doesn't orbit Venus. It orbits the sun.
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My character Tsin'xing
In contrast, a long term exploration vehicle with a self-sustaining environment seems a lot more difficult. Without fairy dust, negative energy or similar exotic materials, it looks to be a slow ride (far) below the speed of light that might take centuries or millenias.
Humanity has yet to build something that can last that long without deteriorating significantly, even less something that could be considered self-sustainable. Heck, I think we haven't even had nations last as long as required...
We can't just import goods from elsewhere, we have to bring all the items and raw materials we are going to need with us. Maybe we can take a few stops along the way, but we're probably still talking years between those. Space is mostly empty. Well, empty in one sense - there is no shortage of stuff that could kill the crew.
Seriously, interstellar exploration of range looks really sad at the moment*. And it's not like our technology hasn't made crazy advancements in the past century. Or 20 years...
My first computer had a 40 MB Hard Disk. A few years ago I got an 8 MB USB Stick, that was what - 1/100th of the size. And last week I got a 64 GB USB Stick that seems to mostly consist out of the USB adapter and an LED - I have no idea where the damn memory is supposed to be stored.
But other technology has not advanced so fast - we don't have car-installed nuclear fission or fusion reactors, our passenger jets don't fly faster than the speed of sound, and we are just now trying to build reusable space craft again, after we have given on our first attempt.
*) And holy fracking sh*t - this universe is incredibly, mind-numbing big. No one has a real sense of how big it is, or at least not me, but even the vague idea of it is still incredible. There are giant intergalactic structures that we'll never be able to visit with our current understanding of the inherent limitations of travel. Even in Star Trek, Stargate or Star Wars FTL capabilities, the universe is still incredibly mind-numbing big and contains spots that seem practically unreachable.
Admittedly, being there might actually be pretty unspectacular - once you've seen a billion of galaxies, it probably gets old. But still, the egocentric or antrophocentric part of me asks- why so big? We can practically see or use nothing of that! WTF, Universe? Are you messing with us?
On the plus side, for energies far less than those involved in moving planets one can easily achieve relativistic velocities, such that travel to another star is easily within the lifespan of the travelers (thanks to the phenomenon of time dilation). Of course, the downside there is that we have yet to discover a star system with any worlds even vaguely approaching Earth - the closest we've found would have a surface gravity of around 1.5g and probably be tidally locked to its star - but then we're only just developing the technologies necessary to see such a world at more than a few lightyears' distance...
An O'Neill cylinder with fusion engines on it is a pretty good starting point for a generation ship--you've got a whole ecosphere that ought to be self-sustaining for centuries as long as you have enough fuel to power your reactors, plus it gives you a decent place to live while you build more cylinders (or terraform) in your destination system, plus it gives you a good place to keep all of your biological samples in situ rather than on ice.
Christian Gaming Community Fleets--Faith, Fun, and Fellowship! See the website and PM for more. :-)
Proudly F2P. Signature image by gulberat. Avatar image by balsavor.deviantart.com.
Going back for a minute to a level of science I feel fairly sure about
Light is also radiation; at first guess you'd expect that a dome that was transparent to light would also be transparent to other and nastier forms of radiation.
Do we currently have materials that are properly transparent to visible light but are opaque to the various dangerous stuff that the Earth's atmosphere and magnetic field normally keep out?
I know ordinary glass is less transparent to infra-red than to visible light (hence why greenhouses heat up: light goes in, is absorbed by the soil and the floor and the energy heats them up, but the heat the warm surfaces radiate doesn't go straight out again because that's infra-red radiation). Checking Wikipedia, ordinary glass is also less transparent to ultraviolet A and completely opaque to the shorter wavelength (i.e. nastier) ultraviolet B and C. (That might actually be a problem to Mars colonists, as ultraviolet B is the part of sunlight that's needed to produce vitamin D - either this would have to be got round or they'd have to rely completely on taking synthetic vitamin D.) I don't know about other wavelengths, off-hand.
Mini-fission reactors small enough to fit in cars have actually been designed, BUT highway safety laws prohibit their use. Something about the danger of radioactive fallout if you wreck....
*points at Concorde* But it was expensive, and may or may not have actually been practical.
And yeah, the US space shuttle program.... was not a viable long term solution. There were a lot of things that really weren't reusable, most importantly the external boosters and heat shield.
My character Tsin'xing
Even if it's "far less", it's still actually a lot, and it's still a possibly insurmountable challenge. If you actually want to benefit from relatistic effects, you need a decent acceleration ,but you can't accelerate much faster than 1g if you want to have humans aboard, and you need to maintain that acceleration for a long time - possibly year. And you need a lot of fuel, to transport yourself and all the fuel you need to transport yourself and all the fuel ...
And once you reach relativistic speed, the vast nothingness of space suddenly is not empty enough anymore, and you have to deal with dangerous particle collisions or high energetic radiation.
The challenges that lie ahead are incredible.
How do you build something that survives those nuclear blasts as often as needed, and will still do it years, decades or centuries later when you arrive in the target system? A solar sail won't slow you down as fast as those nuclear blasts.
The "O'Neill" cylinder is just the name of a hypothetical construct - there isn't yet a construction plan for it.
If we could build this, it would probably be a good idea, but actually suddenly a lot less urgent - if Earth seems to become uninhatbile, the tech required for the cylinder could also be applied on an Earth project. (Even if we can't cover the whole Earth). Only extreme huge asteroid crashes (or small ones that will hit the cylinder directly) and the Sun's demise would still pose concerns. (Even if we have a self-sustaining ecosphere, we probably can't maintain it inside the sun.)
Yes, that's an interesting aspect. We could probably build a dome that could protect us from some or all forms of ration, but maybe we'd cover more than we want? I am not sure what wave lengths plants use for their photosynthesis. (I read a while ago there are actaully two forms of photosynthesis, some plant species use the one, other plants use the other one. But I don't remember what wavelength they used.)
An alternate take is that the dome (if we have them all, this is just one popular concept, but how good is it really?) is just for agriculture - we'd still go with radiation suites outside there, and stay otherwise inside buildings or underground.
If we even need full suites - it depends on how quickly the radiation becomes an actual concern, maybe we'd need just some heavier clothing, or maybe we can just stay unprotected entirely for a few hours each day. Maybe we don't even go out during the day.
Toss some ice at the surface, specifically on one side, so we got the other side of the planet for mining for a few years at least. There's your atmosphere. Use some tech to establish a magnetic shield and people can walk the surface. I'd probably keep the cities shielded though.
I just yesterday learned something very interesting about areography. The northern hemisphere of Mars is markedly smoother than the southern, and apparently averages one kilometer lower in altitude. It's hypothesized that this may be due to a collision with something about the size of Earth's Moon - which also stripped away much of the atmosphere during the collision.
So crashing Ceres into Mars might in fact do exactly the opposite of what you hoped...