A new Astronomy thread

[RobertBlakevsPiersMorgan]

Unfortunately, this event caused someone to die, unlike the spaceship explosion.

Always a loss, yes, but the mission goes on.

"Always a loss"? A guy was torn away from his family. I don't know anything about him, but he could have had a wife and kids--and he died because of some mulleted prick's delusions of grandeur. I never cared much for Dick Branson before this incident, and I sure as hell lost any respect I had for him prior. It's all fun and games for some rich idiot to tinker with toy rockets until somebody dies. This longhaired dumbass should leave space exploration to NASA and other organizations which are specially equipped and staffed by only the most qualified professionals. There was no mission to begin with; it was just some rich kid who outgrew RC airplanes.

[Northwest Slobovia]

Always a loss, yes, but the mission goes on.

"Always a loss"? A guy was torn away from his family. I don't know anything about him, but he could have had a wife and kids--and he died because of some mulleted prick's delusions of grandeur. I never cared much for Dick Branson before this incident, and I sure as hell lost any respect I had for him prior. It's all fun and games for some rich idiot to tinker with toy rockets until somebody dies. This longhaired dumbass should leave space exploration to NASA and other organizations which are specially equipped and staffed by only the most qualified professionals. There was no mission to begin with; it was just some rich kid who outgrew RC airplanes.

*sigh* You do know that America's quest for national glory in space has killed a bunch of people, yes? You do know that there's never been a "mission" there besides a Cold War technological dick-waving contest followed by said "most qualified professionals" flailing about because their fantasies for Mars exploration ran into the cold realities of paying the national bills, and they got a stupid booby prize, right?

The guys who were doing the driving in this case are described as

Both crew members of the spaceship were test pilots for Scaled Composites, the Northrop Grumman Corp subsidiary that designed and built the spacecraft for Virgin and lost three other employees in a July 2007 ground test accident.

The name Scaled Composites may mean nothing to you, but they're one of the world's top aerospace companies, and probably the best in the world for designing, building, and flying composite aircraft, like the ship in question. I'm sorry, if you doubt that they are among the world's "most qualified professionals", you don't know what you're talking about. Branson is doing nothing but providing the money.

I'm also sorry that I believe humanity has a future in space, and that space tourism is going to be part of that. I'd go if I could afford the ride. There's also probably going to be space mining and space factories, and other sorts of profit making ventures, and people are going to die getting those working too. The only way not to lose people doing stuff in space is not to send people into space, and that's not the future I want.

[Grenartia]

"Always a loss"? A guy was torn away from his family. I don't know anything about him, but he could have had a wife and kids--and he died because of some mulleted prick's delusions of grandeur. I never cared much for Dick Branson before this incident, and I sure as hell lost any respect I had for him prior. It's all fun and games for some rich idiot to tinker with toy rockets until somebody dies. This longhaired dumbass should leave space exploration to NASA and other organizations which are specially equipped and staffed by only the most qualified professionals. There was no mission to begin with; it was just some rich kid who outgrew RC airplanes.

*sigh* You do know that America's quest for national glory in space has killed a bunch of people, yes? You do know that there's never been a "mission" there besides a Cold War technological dick-waving contest followed by said "most qualified professionals" flailing about because their fantasies for Mars exploration ran into the cold realities of paying the national bills, and they got a stupid booby prize, right?

The guys who were doing the driving in this case are described as

Both crew members of the spaceship were test pilots for Scaled Composites, the Northrop Grumman Corp subsidiary that designed and built the spacecraft for Virgin and lost three other employees in a July 2007 ground test accident.

The name Scaled Composites may mean nothing to you, but they're one of the world's top aerospace companies, and probably the best in the world for designing, building, and flying composite aircraft, like the ship in question. I'm sorry, if you doubt that they are among the world's "most qualified professionals", you don't know what you're talking about. Branson is doing nothing but providing the money.

I'm also sorry that I believe humanity has a future in space, and that space tourism is going to be part of that. I'd go if I could afford the ride. There's also probably going to be space mining and space factories, and other sorts of profit making ventures, and people are going to die getting those working too. The only way not to lose people doing stuff in space is not to send people into space, and that's not the future I want.

Indeed, its not the future I want, either, because a future without sending people into space is a future where humanity dies on this rock, because we've got all our eggs in one basket. Call me crazy, but I say humanity MUST avoid that fate at all costs, and move out into the galaxy and the universe at large. And the only way to do that is to move out of the atmosphere and into orbit, and then into the rest of the Solar System.

[Brickistan]

Agreed. We really need to get off this planet. The sooner, the better.

Unfortunately, opening new frontiers will always be costly, not just in monetary terms, but also in human lives lost.

[L Ron Cupboard]

Agreed. We really need to get off this planet. The sooner, the better.

Unfortunately, opening new frontiers will always be costly, not just in monetary terms, but also in human lives lost.

But the value of what is out there surely makes it a worthwhile investment?

[Republic of Coldwater]

Agreed. We really need to get off this planet. The sooner, the better.

Unfortunately, opening new frontiers will always be costly, not just in monetary terms, but also in human lives lost.

If we can terraform Mars (and somehow add a very thick atmosphere or a magnetic field), I would be happy with humans moving there. The same goes for the Moon, if we can somehow stop its huge temperature differences and also add a magnetic field.

[Brickistan]

Agreed. We really need to get off this planet. The sooner, the better.

Unfortunately, opening new frontiers will always be costly, not just in monetary terms, but also in human lives lost.

But the value of what is out there surely makes it a worthwhile investment?

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

[Pope Joan]

But the value of what is out there surely makes it a worthwhile investment?

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

[L Ron Cupboard]

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

I don't see the point of wasting billions of dollars, and thousands of lives, fighting over oil in the Middle East when there is so much hydrogen in space.

[Republic of Coldwater]

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

[Brickistan]

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

It's a good point, but what other solution is there?

If we are to stay here, I would estimate that we'd need to reduce the total population to about 2/3 of what it is today in order to keep a stable and sustainable global society. And the need to keep the population capped at that level would mean enforcing some pretty draconian laws on reproduction and resource use.

And even if, by some outlandish miracle, you managed to convinced all of us that this is a good idea, we're still only one really nasty flu or a big lump of space-rock away from total extinction.

The problem, as I see it, is that we currently have all our eggs in one basket. One major catastrophe and it's all over for mankind. The only way to avoid this is to spread our eggs across multiple baskets. It won't be easy. And it will take a lot of sacrifice to get there. But it's the only viable way forward.

[Brickistan]

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

To be honest, I don't really believe in terraforming. It sounds good on paper, but it will take way too long, and cost way too many resources, to be viable on anything but almost-but-not-quite-earth planets.

Certainly, within the solar system, I can't see any viable candidates. There are no other planets / moons with a compatible biosphere.

Better then, I would say, to spend our resources on learning how to cope with ultra-hostile environments. That knowledge will, at the very least, be useful whatever type of planet we encounter.

[Republic of Coldwater]

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

To be honest, I don't really believe in terraforming. It sounds good on paper, but it will take way too long, and cost way too many resources, to be viable on anything but almost-but-not-quite-earth planets.

Certainly, within the solar system, I can't see any viable candidates. There are no other planets / moons with a compatible biosphere.

Better then, I would say, to spend our resources on learning how to cope with ultra-hostile environments. That knowledge will, at the very least, be useful whatever type of planet we encounter.

Well Mars seems likely in my opinion, in the Goldilock Zone, has water that can be melted. If we can bomb the ice caps to release the water and release a lot of oxygen into the atmosphere (plant some trees maybe?), we can migrate humans there. However, deadly solar rays will be an issue, and that requires a magnetic sphere. I don't know how we humans can add a magnetic sphere, since if we can't do so, we will need an ultra-thick atmosphere which is also very costly and inefficient.

[Brickistan]

To be honest, I don't really believe in terraforming. It sounds good on paper, but it will take way too long, and cost way too many resources, to be viable on anything but almost-but-not-quite-earth planets.

Certainly, within the solar system, I can't see any viable candidates. There are no other planets / moons with a compatible biosphere.

Better then, I would say, to spend our resources on learning how to cope with ultra-hostile environments. That knowledge will, at the very least, be useful whatever type of planet we encounter.

Well Mars seems likely in my opinion, in the Goldilock Zone, has water that can be melted. If we can bomb the ice caps to release the water and release a lot of oxygen into the atmosphere (plant some trees maybe?), we can migrate humans there. However, deadly solar rays will be an issue, and that requires a magnetic sphere. I don't know how we humans can add a magnetic sphere, since if we can't do so, we will need an ultra-thick atmosphere which is also very costly and inefficient.

Exactly. Mars' lack of a magnetic field pretty much kills any idea of terraforming it.

It's true that a thick atmosphere would protect, at least to a degree, against radiation. But you'd still lose a lot of the atmosphere due to the solar wind, so you'd need some way to replenish it constantly. Very costly and inefficient, indeed.

Better then, to build shielded self-sufficient habitation areas.

[Immoren]

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

Just build domed and/or underground colonies without bothering with terraforming attempts at least initially.

[Lordieth]

Always a loss, yes, but the mission goes on.

"Always a loss"? A guy was torn away from his family. I don't know anything about him, but he could have had a wife and kids--and he died because of some mulleted prick's delusions of grandeur. I never cared much for Dick Branson before this incident, and I sure as hell lost any respect I had for him prior. It's all fun and games for some rich idiot to tinker with toy rockets until somebody dies. This longhaired dumbass should leave space exploration to NASA and other organizations which are specially equipped and staffed by only the most qualified professionals. There was no mission to begin with; it was just some rich kid who outgrew RC airplanes.

Whatever you think of Richard Branson, I very much doubt this was the result of carelessness. Think of all the people who have died in NASA flights. Or aviation test flights. These pilots are pushing the frontiers of aviation, and they risk their lives to do it. Those "specially equipped" organisations have resulted in a great many deaths, all in the name of progress.

This is the reality of pushing the boundaries of travel.

[Northwest Slobovia]

But the value of what is out there surely makes it a worthwhile investment?

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

Oh, at least. There are three things that are really expensive about spaceflight now:

1) Moving between the Earth's surface and Earth orbit. This requires vessels that can take off from the surface (high thrust-to-weight propulsion systems that can work in atmosphere and a streamlined shape) and return (survive re-entry, which requires fancy materials and a funny shape, and land, ideally on solid ground).

2) Moving between Earth orbit and some other body. This is really a problem because with our current engines, flight times are very long, which leads to the expense of:

3) Keeping people alive in space. We really suck at this. We can't even quite recycle air and water aboard the space station, much less provide food or gravity for people aboard. It's not clear we can practically build ships that can protect their crew from solar storms. (The space station is protected by the Earth's magnetosphere, and the Apollo missions were carefully timed to avoid solar flares.)

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

Well...

a) Other than Harrison Schmidt -- a geologist who went to the moon on Apollo 17 -- all knowledge we've gained about space has been done with machines in space and/or people on Earth. There's not much reason to put people in space for the kinds of exploration we're doing. (That might change if we find life elsewhere in this solar system, but even then, we'd send as few people as possible; see 2 and 3, above.)

b) NASA isn't doing much on the gaining knowledge front otherwise. I hate to say it, but we've learned precious little about human survival in space since the Skylab and Salyut missions. And they're not very interested in reducing the cost of spaceflight. A few people and their companies are (Elon Musk and his SpaceX, notably).

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

Unfortunately, the kind of resources we need here -- especially those leading to the current extinctions -- are biological, mostly farming. I have no idea -- none at all -- how we'd make farming in space anywhere close to cheap enough to help with that.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

Death Valley is very pretty, and perfectly habitable so long as you avoid the valley floor in the summer. The Timbisha (Native Americans) have lived there for quite some time. But Death Valley -- or even the middle of the Sahara -- are way more habitable than anywhere in space.

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

To be honest, I don't really believe in terraforming. It sounds good on paper, but it will take way too long, and cost way too many resources, to be viable on anything but almost-but-not-quite-earth planets.

I'll be more blunt: all talk about terraforming is wishful thinking. We don't know how to do it -- all proposals to do so are just that: proposals, usually with more handwaving than fact -- nor do we know how long it would take nor how much it might cost. But you're right that the serious BOTECs tend to end up with times of thousands of years, and costs of many multiples of the Earth's GDP for decades to centuries.

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

Just build domed and/or underground colonies without bothering with terraforming attempts at least initially.

Much more sensible, though why not start with the big deserts, alpine mountains, and icy wastes here? They're much easier test cases, and if when things go wrong -- like they did with "Biosphere 2" -- it's easy to rescue people and then send follow-up teams to figure out what went wrong.

[Brickistan]

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

Well...

a) Other than Harrison Schmidt -- a geologist who went to the moon on Apollo 17 -- all knowledge we've gained about space has been done with machines in space and/or people on Earth. There's not much reason to put people in space for the kinds of exploration we're doing. (That might change if we find life elsewhere in this solar system, but even then, we'd send as few people as possible; see 2 and 3, above.)

b) NASA isn't doing much on the gaining knowledge front otherwise. I hate to say it, but we've learned precious little about human survival in space since the Skylab and Salyut missions. And they're not very interested in reducing the cost of spaceflight. A few people and their companies are (Elon Musk and his SpaceX, notably).

a) In this case, I was thinking more about practical knowledge of surviving in ultra-hostile environments. For purely scientific endeavors, I would mainly agree with you - that can be handled by robots.

b) NASA has, unfortunately, been starved of resources for a very long time now. Indeed, had it been given just a fraction of what the US military industrial complex gets, we could very well have had manned missions to Mars by now.


Both issues, really, are down to a lack of will on the part of politicians. Sadly, these days there just isn't much interest in doing basic science and exploration.

[Northwest Slobovia]

Well...

a) Other than Harrison Schmidt -- a geologist who went to the moon on Apollo 17 -- all knowledge we've gained about space has been done with machines in space and/or people on Earth. There's not much reason to put people in space for the kinds of exploration we're doing. (That might change if we find life elsewhere in this solar system, but even then, we'd send as few people as possible; see 2 and 3, above.)

b) NASA isn't doing much on the gaining knowledge front otherwise. I hate to say it, but we've learned precious little about human survival in space since the Skylab and Salyut missions. And they're not very interested in reducing the cost of spaceflight. A few people and their companies are (Elon Musk and his SpaceX, notably).

a) In this case, I was thinking more about practical knowledge of surviving in ultra-hostile environments. For purely scientific endeavors, I would mainly agree with you - that can be handled by robots.

I think I understand your emphasis on hostile environment survival, but I'm not sure that that's going to get many people into space. If we reason from what we know on Earth, the more hostile the environment, the more expensive it is to keep somebody alive there. Since space seems very hostile, the implied cost would argue for very few people in space.

Immoren's point above about building domed cities on a planetary surface seems like a reasonable approach, assuming there's an economic reason for there to be a city on the planet in the first place. The Martian surface is pretty harsh, but it's easier to survive there than on a space station or on the surface of an airless moon or asteroid.

b) NASA has, unfortunately, been starved of resources for a very long time now. Indeed, had it been given just a fraction of what the US military industrial complex gets, we could very well have had manned missions to Mars by now.

Both issues, really, are down to a lack of will on the part of politicians. Sadly, these days there just isn't much interest in doing basic science and exploration.

That's another point I'm going to have to start my answer to with "Well...".

Sure, NASA's budget is "only" $20G/yr, compared to the military's ~$650G/yr budget, but that's a lot of research! And NSF is providing a steady billion dollars a year for astronomy.* That's pretty amazing, I think: it means every taxpayer is, on average, kicking in $10/yr to do nothing more than buy telescopes. That's pure basic research. (*: Personal communication from my friendly neighborhood astronomer.)

As to Mars missions, one of the things we learned from Curiosity is that the interplanetary radiation environment is a lot harsher than we thought, even during periods of "quiet sun". The same is true for the Martian surface. I have a bad feeling that if we'd sent Mars missions in the late 70's like NASA wanted, we would have killed a lot of guys because we didn't understand how hard the problem is.

[Northwest Slobovia]

Actual astronomy: Since it's getting towards winter Orion will start to rise soon. Since it's the brightest constellation in the northern sky, I thought I'd post a link to some pretty pictures of of the Orion nebula. Direct link to very large version of the first one; too big for NS to display.

The Orion nebula is the middle "star" of Orion's sword, and is pretty easy to see with a small telescope. Near Orion is Taurus, containing the nearby bright star Aldebaran and the Hyades, the nearest open star cluster. And near Taurus is the Pleiades, another nearby (and very pretty) naked-eye star cluster.

[Grenartia]

Depends on how you measure value.

In purely monetary terms, then yes, there's plenty of value out there. Water, minerals, etc. can all be mined and sold by private corporations. Unfortunately, right now we're still a very long way from the point where it's worthwhile doing so due to the high cost of achieving orbit.

That's why we need government organisations such as NASA and ESA. Right now we're at a point in time where we need to do this, not to turn a profit, but simply to gain knowledge.

However, I'm actually thinking more in terms of surviving as a species. When I was a child I was deathly afraid of a big meteor hitting earth and killing us all, just as what happened to the dinosaurs. These days, however, I tend to see mankind as the bigger threat.

Indeed, we're currently seeing the sixth big extinction level event happening right before our eyes. And we're largely to blame for it. If we don't want to go the way of the Dodo, then we need to clean up our act and get the hell out of Dodge, so to speak. We're pushing earth's resources way beyond the breaking point as it is now, and it's only going to get worse as the population keeps growing.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

False dichotomy.

The fallacy of your comparison is that Earth is too crowded, and there's nowhere else we know of that's even remotely like it in terms of its ability to harbor life, to say nothing of being able to reach those places.

Whereas in the apartment comparison, there are literally thousands of other places that you know about that are habitable.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

I don't see the point of wasting billions of dollars, and thousands of lives, fighting over oil in the Middle East when there is so much hydrogen in space.

Not to mention that clever use of resources can allow us to put large farms in orbit (the right polar orbit can allow practically limitless growing seasons), allowing us to produce enough food for everybody. The moon can provide us with extra living space under the surface. I could go on.

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

The moon can't be terraformed. We'd have to go under the surface. Mars and Venus would be excellent candidates, though the process would have to be more complex than is normally assumed.

Venus needs to be bombarded with comets nearly constantly (which would have to come from the Oort cloud) in order to change its atmosphere (unless you want to build floating cities in the upper atmosphere, which we could do today if we had the will), and Mars needs to have its magnetic field kickstarted or generated somehow, in addition to standard terraforming. I'll leave it up to you to figure out which process would be more expensive.

I don't see the point in moving to a hostile unwelcoming environment on a dead planet in order to save my species.

it's like saying "My apartment is too crowded, so I'm moving to Death Valley".

It's a good point, but what other solution is there?

If we are to stay here, I would estimate that we'd need to reduce the total population to about 2/3 of what it is today in order to keep a stable and sustainable global society. And the need to keep the population capped at that level would mean enforcing some pretty draconian laws on reproduction and resource use.

And even if, by some outlandish miracle, you managed to convinced all of us that this is a good idea, we're still only one really nasty flu or a big lump of space-rock away from total extinction.

The problem, as I see it, is that we currently have all our eggs in one basket. One major catastrophe and it's all over for mankind. The only way to avoid this is to spread our eggs across multiple baskets. It won't be easy. And it will take a lot of sacrifice to get there. But it's the only viable way forward.

Exactly. Colonization is the ONLY viable solution.

To be honest, I don't really believe in terraforming. It sounds good on paper, but it will take way too long, and cost way too many resources, to be viable on anything but almost-but-not-quite-earth planets.

Certainly, within the solar system, I can't see any viable candidates. There are no other planets / moons with a compatible biosphere.

Better then, I would say, to spend our resources on learning how to cope with ultra-hostile environments. That knowledge will, at the very least, be useful whatever type of planet we encounter.

Well Mars seems likely in my opinion, in the Goldilock Zone, has water that can be melted. If we can bomb the ice caps to release the water and release a lot of oxygen into the atmosphere (plant some trees maybe?), we can migrate humans there. However, deadly solar rays will be an issue, and that requires a magnetic sphere. I don't know how we humans can add a magnetic sphere, since if we can't do so, we will need an ultra-thick atmosphere which is also very costly and inefficient.

As I recall, Venus is on the very inner edge of the Goldilocks Zone, so it could be viable as well.

But Mars has a lot more inherent challenges to terraformation than Venus. For one, Mars's gravity is significantly lower than Earth's so simply "adding moar O2/water/etc." won't work, and might backfire, since CO2 atmospheres tend to have higher pressures, IIRC. Lose that pressure, and any liquid water boils away faster than it would now. Second, the other consequence of the lack of a magnetosphere is that the Solar wind will keep knocking away any Earthlike atmosphere you install (the upper limits of which will most certainly be higher than Mars's current atmosphere, and probably higher than even Earth's, since pressure depends on density, and since you're replacing an atmosphere of a dense gas with one of a less dense mixture, you're going to need more volume to get the same pressure (or higher) as the original).

The only way I could think to restart the magnetic field would be to wrap some cables around the core, and use orbiting solar power plants connected to the surface via space elevators to maintain power to your giant electromagnet. Of course, you'd probably have to harvest every bit of raw material from at least several dozen city-killer (1km or bigger) asteroids in order to get the material for the cables and solar arrays, to say nothing of the problems with cooling the entire damn thing off.

The only problem with terraforming Venus is getting enough comets to impact the surface quickly enough to keep the momentum going as far as changing atmospheric composition goes. The main expense here is with fuel costs and building a large enough vessel, though the basics can probably be done by most people who play Kerbal (after all, its only cosmetically different from the Asteroid Redirect Mission).

Well Mars seems likely in my opinion, in the Goldilock Zone, has water that can be melted. If we can bomb the ice caps to release the water and release a lot of oxygen into the atmosphere (plant some trees maybe?), we can migrate humans there. However, deadly solar rays will be an issue, and that requires a magnetic sphere. I don't know how we humans can add a magnetic sphere, since if we can't do so, we will need an ultra-thick atmosphere which is also very costly and inefficient.

Exactly. Mars' lack of a magnetic field pretty much kills any idea of terraforming it.

It's true that a thick atmosphere would protect, at least to a degree, against radiation. But you'd still lose a lot of the atmosphere due to the solar wind, so you'd need some way to replenish it constantly. Very costly and inefficient, indeed.

Better then, to build shielded self-sufficient habitation areas.

Most likely in underground caverns or caves.

Which planet/moon within the Solar System do you guys think are the best candidates for terraforming if we had the cash and the resources to undertake such a task?

Just build domed and/or underground colonies without bothering with terraforming attempts at least initially.

Domes are too risky for anything other than being above-ground recreation areas (gotta keep up morale somehow, and I don't care how many mutant 3-titted hookers you have, you need something else) sealed off from the main living spaces.

a) In this case, I was thinking more about practical knowledge of surviving in ultra-hostile environments. For purely scientific endeavors, I would mainly agree with you - that can be handled by robots.

I think I understand your emphasis on hostile environment survival, but I'm not sure that that's going to get many people into space. If we reason from what we know on Earth, the more hostile the environment, the more expensive it is to keep somebody alive there. Since space seems very hostile, the implied cost would argue for very few people in space.

Immoren's point above about building domed cities on a planetary surface seems like a reasonable approach, assuming there's an economic reason for there to be a city on the planet in the first place. The Martian surface is pretty harsh, but it's easier to survive there than on a space station or on the surface of an airless moon or asteroid.

b) NASA has, unfortunately, been starved of resources for a very long time now. Indeed, had it been given just a fraction of what the US military industrial complex gets, we could very well have had manned missions to Mars by now.

Both issues, really, are down to a lack of will on the part of politicians. Sadly, these days there just isn't much interest in doing basic science and exploration.

That's another point I'm going to have to start my answer to with "Well...".

Sure, NASA's budget is "only" $20G/yr, compared to the military's ~$650G/yr budget, but that's a lot of research! And NSF is providing a steady billion dollars a year for astronomy.* That's pretty amazing, I think: it means every taxpayer is, on average, kicking in $10/yr to do nothing more than buy telescopes. That's pure basic research. (*: Personal communication from my friendly neighborhood astronomer.)

As to Mars missions, one of the things we learned from Curiosity is that the interplanetary radiation environment is a lot harsher than we thought, even during periods of "quiet sun". The same is true for the Martian surface. I have a bad feeling that if we'd sent Mars missions in the late 70's like NASA wanted, we would have killed a lot of guys because we didn't understand how hard the problem is.

I don't know, I'd say a sublunarian (geddit, cuz its on the moon!) habitat is pretty feasible. All you have to do is send in a few robots to excavate the cavern (which only needs to be far enough under the surface to block the incoming solar radiation), then install an airlock at the entrance. Fill the interior with an easily detectable gas that won't be toxic to the inhabitants in small traces, and isn't the byproduct of any radioactive decay, to detect any leaks in the living space. Then send in the manned teams to seal the leaks (if any), vent the detector gas, and install the interior equipment.

[Northwest Slobovia]

I don't know, I'd say a sublunarian (geddit, cuz its on the moon!) habitat is pretty feasible. All you have to do is send in a few robots to excavate the cavern (which only needs to be far enough under the surface to block the incoming solar radiation), then install an airlock at the entrance. Fill the interior with an easily detectable gas that won't be toxic to the inhabitants in small traces, and isn't the byproduct of any radioactive decay, to detect any leaks in the living space. Then send in the manned teams to seal the leaks (if any), vent the detector gas, and install the interior equipment.

While plausible, we'll have to invest the 5000 Research Points in Advanced Robotics first. We'll get right on it!

But seriously, yes, both NASA and the Air Force looked a underground bases on the moon. I have no doubt you could build one if you wanted one. They're gonna be expensive, though, since that's the nature of underground construction.

Building on (in) Earth's moon (as opposed to damn near everywhere else in the solar system that tunnelling might work) gets you two of the advantages of planetary surfaces: cheap radiation shielding (as you said) and a worthwhile amount of free gravity. However, while underground construction is fine for small, special-purpose facilities (mines, observatories, missile bases) it's not so good as a toe-hold for larger-scale settlement of the moon, because they are so expensive to construct and expand.

[Monkeykind]

I don't know, I'd say a sublunarian (geddit, cuz its on the moon!) habitat is pretty feasible. All you have to do is send in a few robots to excavate the cavern (which only needs to be far enough under the surface to block the incoming solar radiation), then install an airlock at the entrance. Fill the interior with an easily detectable gas that won't be toxic to the inhabitants in small traces, and isn't the byproduct of any radioactive decay, to detect any leaks in the living space. Then send in the manned teams to seal the leaks (if any), vent the detector gas, and install the interior equipment.

While plausible, we'll have to invest the 5000 Research Points in Advanced Robotics first. We'll get right on it!

But seriously, yes, both NASA and the Air Force looked a underground bases on the moon. I have no doubt you could build one if you wanted one. They're gonna be expensive, though, since that's the nature of underground construction.

Building on (in) Earth's moon (as opposed to damn near everywhere else in the solar system that tunnelling might work) gets you two of the advantages of planetary surfaces: cheap radiation shielding (as you said) and a worthwhile amount of free gravity. However, while underground construction is fine for small, special-purpose facilities (mines, observatories, missile bases) it's not so good as a toe-hold for larger-scale settlement of the moon, because they are so expensive to construct and expand.

Don't forget the ahead of time penalty.

[Northwest Slobovia]

While plausible, we'll have to invest the 5000 Research Points in Advanced Robotics first. We'll get right on it!

But seriously, yes, both NASA and the Air Force looked a underground bases on the moon. I have no doubt you could build one if you wanted one. They're gonna be expensive, though, since that's the nature of underground construction.

Building on (in) Earth's moon (as opposed to damn near everywhere else in the solar system that tunnelling might work) gets you two of the advantages of planetary surfaces: cheap radiation shielding (as you said) and a worthwhile amount of free gravity. However, while underground construction is fine for small, special-purpose facilities (mines, observatories, missile bases) it's not so good as a toe-hold for larger-scale settlement of the moon, because they are so expensive to construct and expand.

Don't forget the ahead of time penalty.

Damn! Y'know, I always do. Let's see... hm, 10 extra turns. *hmph!*

[Monkeykind]

Don't forget the ahead of time penalty.

Damn! Y'know, I always do. Let's see... hm, 10 extra turns. *hmph!*

Let's see...+3%? So 5150.