Colonizing Mars

[marsbug]

I think you've been fed some bad info there, D-type asteroids might have some water content, but thats not really proven yet, and we don't know how much. Soft landing one on the martian surface would take a really phenomenal amount of power. Why go to all that bother when mars has massive amounts of water ice on or near the surface anyway?

My two cents is that the first step on the road to colonising mars is getting something to live on the surface, and I think thats a great goal in its own right. I think we should be looking at small things to get the ball rolling, rather than leaping to massive astro engineering projects like full terraforming.

[cjameshuff]

Also, those asteroids constitute an enormous quantity of useful resources already conveniently in orbit. In destroying them (and doing an enormous amount of additional work, bombarding Mars with asteroids isn't enough), you make a planet temporarily borderline-inhabitable (survivable, not comfortable), provided you keep up the maintenance.

You also destroy the massive deposits of CO2 and water ice on Mars itself, and easily-accessible surface deposits of water-soluble minerals, all of which are potentially of extreme value for fuel, farming, production of polymers, etc. You now have a thick atmosphere that blocks much of the thin sunlight needed by plants or solar powered equipment, and you've replaced the feeble dust storms with blizzards, thunderstorms, and other Earth-like weather.

Basically, by terraforming Mars, you are going to great expense to make Mars more difficult to live on while simultaneously removing many of the reasons to live there.

[Ara Pacis]

Also, those asteroids constitute an enormous quantity of useful resources already conveniently in orbit. In destroying them (and doing an enormous amount of additional work, bombarding Mars with asteroids isn't enough), you make a planet temporarily borderline-inhabitable (survivable, not comfortable), provided you keep up the maintenance.

You also destroy the massive deposits of CO2 and water ice on Mars itself, and easily-accessible surface deposits of water-soluble minerals, all of which are potentially of extreme value for fuel, farming, production of polymers, etc. You now have a thick atmosphere that blocks much of the thin sunlight needed by plants or solar powered equipment, and you've replaced the feeble dust storms with blizzards, thunderstorms, and other Earth-like weather.

Basically, by terraforming Mars, you are going to great expense to make Mars more difficult to live on while simultaneously removing many of the reasons to live there.

Are you saying we shouldn't terraform Mars? Are you one of those tin-can nuts?

[neilzero]

I suppose there are some one part per million things we can do near the end of this century, such as increase the average light level with some pilot staytites near Mars. We could put a few tons of CFC in the atmosphere. Perhaps neither would produce measurable results, but we might be surprised.
Death valley is hot partly because it is below sealevel, so we can excavate some already low areas near the Equator, to enhance the temperature, then plant some genetically altered crops. Likely we will need artificial heat a few days shortly before sun rise, and irrigation most every day, but this gives us some bench marks on what our minimum effort is. Likely there is adequite carbon dioxide and some plants can thrive with negligible oxygen in the air. A ten times increase in air pressure will permit selected humans to use just an oxygen mask for a few minutes in Mars atmosphere. That is still very low air presure, but a big improvement over a full space suit, but it will iikely take centueies to get a ten times increase in air pressure. Neil

[Noclevername]

Wow, digging up an old fossil here, Neil!

[Van Rijn]

We could put a few tons of CFC in the atmosphere. Perhaps neither would produce measurable results, but we might be surprised.

it would require quite a lot more than a few tons of CFC to have a significant effect. Also, CFCs have a much shorter residence time on Mars than on Earth, due to the higher UV (no protective ozone layer), so constant production would be needed. It would require a very large industrial capacity, and it isn't at all clear the benefits would outweigh the drawbacks.

[Noclevername]

I suppose there are some one part per million things we can do near the end of this century, such as increase the average light level with some pilot staytites near Mars. We could put a few tons of CFC in the atmosphere. Perhaps neither would produce measurable results, but we might be surprised.

I doubt we'd be doing any terraforming this or even next century-- there's just too much we don't know about Mars in its present state to just start throwing massive global changes at it. We don't even know what those recurring dark spots near the poles are.

Death valley is hot partly because it is below sealevel, so we can excavate some already low areas near the Equator, to enhance the temperature, then plant some genetically altered crops. Likely we will need artificial heat a few days shortly before sun rise, and irrigation most every day, but this gives us some bench marks on what our minimum effort is. Likely there is adequite carbon dioxide and some plants can thrive with negligible oxygen in the air.

Plants can't survive in a near-vacuum, which Mars' atmosphere is even at the lowest altitudes. We'd have to dig miles deep to make it thick enough for plant life to survive.

The trouble with terraforming an already-colonized Mars it that it's going to create chaotic conditions that would endanger the settlers already there. They'd likely be in the areas that would be most affected by the radical environmental changes-- low-lying ground and areas with signifigant amounts of water ice. Thickening the atmosphere will also increase the amount of dust carried by dust storms.

[potoole]

Unfortunately, Mars is no where near as close to us as the moon. So even though the gravity situation is worse on the moon, it still serves as a better testbed than any other body in the solar system. I have faith that the human race can overcome the obstacles needed to colonize the moon and simulate gravity on the moon. If we can do it on the moon, than simulating gravity should be easier to do when we get to Mars since, as you insisted, is less of a problem.

How could gravity be simulated? Or how could it be intensified on Moon or Mars colonies?
Will it be possible to do so?

[Noclevername]

How could gravity be simulated? Or how could it be intensified on Moon or Mars colonies?
Will it be possible to do so?

Possible but impractical-- hypothetically a large "bullet train" could be sent around a crater rim at extremely high speeds to produce spin "gravity". However this would require enormous amounts of power and constant maintainance. It would have limited passenger capacity.

[Ara Pacis]

It wouldn't really take a lot of industrial capacity to build a statite to reflect sun to the poles and nightside of Mars. Well, that all depends on how fast you want it done. However, just using a single calender running full time to make rolls of aluminum foil (simple and cheap to make from lunar aluminum) we could make a huge reflector array in decades. A single industrial roll of standard foil is ~1m wide and can be upwards of 8 miles in length (depending on how thin you want it), and about 78 of those is one square kilometer. That sounds like a lot, but an aluminum foil rolling mill can move that foil at speeds up to 2500m/min, which means that 12,875m roll would be finished in 5.15 minutes (and some of those machines can do 2m widths). That would allow a square kilometer worth of foil to be made in 6 hours 40 minutes minus roll changes (half that if the roll is 2m). The 250km diameter mirrors that some scientists say we might need would take about 37.3 years to build with a single machine and 1m rolls, 18.7 years with 2m width rolls (not including other structural elements that can be made in other machines concurrently.

I suspect that colonists will know ahead of time that terraforming is a possible goal and will choose sites with that in mind, such as bedrock or on a dry-dirt hill above a basin. Or they may have mobile habs. More permanent structures will need to have environmental impact studies before hand, and may need pilings put deep into the ground if mechanical effects from volatile fluids is predicted to be possible in that location.

And to answer potoole's question, yes, we can spin a habitat on the ground to increase the gravity experienced by people in that hab. It might have to be a few hundred meters in diameter though.