Mars Colonies are a Fantasy

[YetAnotherBob]

...

"We might even do something about the muscle and skeletal atrophy problem simply by wearing heavily weighted clothing to simulate Earth normal gravity."

That's highly unlikely. The effects of low gravity are quite similar to long term bed rest. That can be treated. It takes months or even years to recover however. Muscle atrophy, cardiovascular issues, calcium loss in bones, yeah, it's all there. It's all treatable too, and has been for a couple of generations now. But the Physical Therapy involved is long and not always easy. The months can drag on into years.

That however is not a problem for those who don't intend to come back to Earth. Colonists won't mind having bones that are just strong enough for Mars. Not if they want to be Martians.

Your problem is that you are assuming that everyone there will want to return to Earth. But why cripple yourself while you are on Mars to make things easier when you return to Earth. Just don't come back. Problem solved.

"Like living in Antarctica"

Nobody lives in Antarctica because there are international treaties forbidding it, except for scientific researchers. In the High Arctic there are tens to thousands living under almost exactly the same conditions.

As I said in an earlier post, Living on mars isn't like living in Antarctica. No, it's going to be more like living in the Mall. The earlier years will be more like living in a warehouse, but the warehouse will grow and become somewhat more specialized. The first couple of years will be living in a small house. Island Fever is easy by comparison.

"But families? Is it moral to risk your kids' lives when they have no say in the matter? Do we see kids living in Antarctica or under the ocean? Of course not!"

The same could be said about having Kids in the USA for emigrants from Europe of Asia. Oh, and the population of the US, Europe and all of Northern Asia is declining. It seems having kids is out of style. Too bad, as the future only belongs to the children. If you have no children, you have no future. The same will be true for Mars.

But looking around at the shopping mall, kids don't seem to mind the environment most like a Mars Colony here on Earth at all. So yes, it is moral to have kids and to raise them to live as well as they can where they are.

". . . like the deserts of the American Southwest. But it's not. It's not even as fun as the Sahara, and I don't see anyone living there except in oases."

Speaking as someone who lives near Phoenix Arizona, with enough tech, it's easy to live in the hot dry deserts. The problems with the Sahara are not technical, they are political.

Benito Mussolini forced some Italians to live in the Sahara Desert in the 1930's. They had little problem dealing with the desert conditions. Drinking water was from solar stills. Grasses with no goats (The Sahara is a goat made desert for the most part. It's a dramatic demonstration of overgrazing) survived and spread about a kilometer a year. There are still the occasional research project that proves the assertion. Get rid of the goats, sheep, cattle and most of the horses, and the Sahara could be restored to the grassland with the occasional swamp and lake that it was in 1200 BC.

The Arabs who lived there were quite upset with the Italians over that however. With good cause. The nomads living there were herders mostly. The Italians didn't care what happened to the herders. They just killed the goats and sheep.

The lesson there isn't that Mussolini was a good guy, he wasn't. The lesson was that the Sahara can be settled if we really want to. But the problems with that need political solutions that will allow those now living there to survive as the landscape is changed.

But there are several millions living in or next to the Sahara today.

Mars has other problems. But they are problems that are solvable.

Check with the Mars Society. They have nearly everything worked out, except for the power problem.

Solar works for Mars about as well as it does on Earth. It's just as bad too. Solar had problems. Just look up the 'Duck'.

Nuclear works for Mars, but politically we can't ship the materials there, and we don't have the sources on mars to make it there. We won't for at least fifty years.

Fusion would solve all the problem if it worked. So far it doesn't.

Hydrocarbons don't work, as there isn't a ready oxygen supply.

So the problem that will most likely doom the first Mars Colony is the Power Problem. All the others are already solved.

Mars is not easy, but can be done. Barely.

 

[YetAnotherBob]

I really don't think the Americas are a good template for Mars. There's just no comparison. Europeans didn't colonize the Americas. They conquered the humans who had already colonized the Americas thousands of years earlier. The Europeans were just moving in to a section of Earth that they hadn't known about before.

Once we colonize the other 2/3 of our planet, the alien lands under the seas, then we might have the skills to colonize other planets. And those lands are close by, with easy to convert air and water, normal gravity. Easy! And lots of close by mineral resources. So where are the colonies?

A popular view but not a correct one. The Spanish did enslave the native populations, or killed them off and replaced then. The English just moved in. Most of the natives killed each other or died of disease. It was European diseases that made this possible. For the first hundred years, the native 'Indians' beat the English back repeatedly.

The colonization of North America by the English isn't an exact analogue for the colonization of Mars, but it is the best example we have. The Spanish in Mexico and South America and the Portuguese in Brazil and to a lesser degree the French are more like your supposition of what actually happened.

The English didn't enslave any Indians in North America, and in fact up to the revolution in 1776, they were allied to some of the stronger tribes. That changed after the Jackson Presidency.

 

[Jackie Cox]

Even a very bad climate change/global warming devastated day, a day on Earth is far more survivable than a day on Mars. Always has been. Always will be. So the excuse that Mars is Plan B if Earth fails is not tenable. Earth will not fail. It'll give us a whupping from time to time to keep us in our place, but we'll figure out a work around. That's going on right now!

There is plenty of water on Mars though it needs some modification to be drinkable. We can manufacture an artificial atmosphere from that water plus the MARS' CO2. We can escape the radiation by living underground. We can grow food underground using zig-zag light tubes with mirrors to get the light to the plants while those nasty cosmic proton bullets eat dirt.

We can protect in-transit humans either with water stored around the hull of their ship or by using some sort of artificial anti-radiation shield, technology that is currently being researched.

We might even do something about the muscle and skeletal atrophy problem simply by wearing heavily weighted clothing to simulate Earth normal gravity.

But we still get to the issue of What's the Point? People dream of Mars because they see it as some new frontier, like the deserts of the American Southwest. But it's not. It's not even as fun as the Sahara, and I don't see anyone living there except in oases. Otherwise, they're just passing through.

Living on Mars is somewhat like though harder and more constrained than living under the ocean or in Antarctica. So I see those two places as templates of what people will really do on Mars. Most people there will be scientists living there for 2 years at a stretch to study it. Geologists will be in hog heaven! But there are other disciplines that would find it fascinating, too.

But families? Is it moral to risk your kids' lives when they have no say in the matter? Do we see kids living in Antarctica or under the ocean? Of course not! What we see are single persons or couples staying on site for a set amount of time and then going back home.

Tourists? We do see them visiting Antarctica and under water venues, but I doubt that we'll see many of them on Mars until the round trips get a lot shorter.

Without a sustainable gravitational field, Mars is without an atmosphere as solar winds and radiation create conditions unsuitable for life forms.

This popular Mars Colony thought is fostered by things Published = model to send millions to Mars on spacecraft fleets every 26 days when earth lines up with Mars, as if we could simply go there when the planets align, ignoring the reality of real time and space variables.

it looks like an effort to get at the Tax Dollar to further creating personal wealth or whatever by playing the Science Fiction Game.

Jupiter’s Moons are far more habitable with Calisto being a more probable candidate for space exploration.

Earth is a Wonderful Creation, It’s an ongoing pleasure to marvel at our nature, and the raw materials it provides to bring us into higher qualities of Life.
If people really wanted to develop a colony under some planets surface, a more likely place to begin is on earth by developing underground colony without relying on earths surface for survival. Then repeating it on a lunar subsurface colony.

spaceX published plans to use Russian Rocket architecture with earths fuels to get there and back isn’t well thought out.

we might want to consider further development of Hydrogen Nuclear Energy reactors and new aerospace propulsion systems that could actually go there and back without a Commercial fuel supply of unbelievable proportions in weight and size necessitating an unimaginable rocket in size and fuel consumption to just get off earth.

it’s difficult to understand the plan published like a comic book without any real Timeline where all known variables are used to create a virtual matrix in order to develop a viable plan

 

[YetAnotherBob]

Better rockets would be great! Do you know how to build one? Oh, and if it's nuclear, what is the radioactive product release? (there is always some).

Fusion would be wonderful. Too bad it doesn't work yet.

I've seen plans for engines based on the Bhagavad Gita , or some UFO ideas. They all have one thing in common, they don't work.

I've also seen plans for engines based on extreme physics ( Impossible Drive, Einstein-Mach, etc. They all have one thing in common. The thrust produced is just above zero. Chemical rockets work better.

I've been to the site of the NERVA rockets. They leaked plutonium.

So we appear to be stuck with the 'comic book' rockets. They will get us to Mars (barely), but not further.

To get robot explorers beyond Mars, we had to use Gravity Assist. Good alignments occur only every eight to one hundred years. There was the best in a century and a half in the late 1970's. That's when we launched the 'Grande Tour' that explored all the outer planets.

So I would love to see this better technology you speak of.

But as it stands, I don't see it.

 

[Jackie Cox]

Current NASA development of Hydrogen Fueled Plutonium/Uranium Rocket is more viable than 70 years ago, plus it can carry enough Liquid hydrogen to fuel rocket for years. New materials, manufacturing processes bring us closer to a reactor where a Liquid Hydrogen can be stored in its -250 degree C

 

[Ken Fabian]

Who is going to pay for it?

I think the argument just goes in circles. I don't think Mars colonies can work but i don't think the Mars optimists will take any of the arguments for why on board; in order to sustain the dream they cannot. I too, see the economics as unworkable and if it isn't economically viable it is not viable.

FWIW - Sea shipping works on freight rates under US$100 per ton between distant major ports. With extraordinary improvements we might manage freight rates between Mars and Earth of under US$1,000,000 per ton. That is not conducive to trade sufficient to support a high tech reliant colony in extreme conditions at a vast distance. Self sufficiency as a starting state for a Mars colony is not credible. My own view is that only a large, comprehensively capable industrial economy can make the essential technology for self sufficiency under such conditions. "Bootstrapping" style improvising as you go cannot substitute.

I think it is a lot like Antarctica or the Atacama - and whilst there is mining in the Atacama and potentially (should treaties change) in Antarctica, these are provisioned and supported by the global economy surrounding them and could not exist let alone persist without it.

Any attempt to make a self supporting colony in these kinds of remote places can only succeed through a long period of profitable and enduring trade and cannot start with self sufficiency.

Mars is even less like North America, which, besides having fertile soils with air and water and an abundance of readily usable resources to support low tech survival, was in reach of European trade, using existing, well proven, low cost technology of the time.

 

[YetAnotherBob]

The question is "what will be the correct path for future space development"?

Actually,the correct answer to 'Should we colonize the Moon, Mars the Asteroids or some space based habitat' is yes, all of the above.

The Moon is the obvious first choice. It has a lot of material resources, it is also closer than any other destination. Developing the Moon will teach us what we need to survive long term in space.

But the Moon has very little nitrogen. Nitrogen is vital to life. So the Moon will never be able to sustain itself without constant re-supply from Earth.

Mars has everything the Moon has, but it also has nitrogen. Limited supplies, yes, but there are millions of tons of nitrogen there that only needs an air compressor to get it. So Mars can survive without Earth.

Mars however will never have a 'shirtsleeve' environment. It hasn't enough air. Without some powerful technology that we can calculate, but can't currently construct, it never will.

But that's OK to an indoor civilization. Mars hasn't much atmosphere. It has enough though to support a few Billion people. It also has much easier access to space. It takes about a tenth the rocket to reach orbit around Mars than it takes around Earth.

New York is almost an indoor civilization. So is Tokyo and Hong Kong. So too is Singapore. Each of them would just need some sealed walkways between buildings to be a good analogue to Mars in all but the industrial sector.

What we shouldn't do is spend hundreds of billions to build up Mars quickly. Spend that on the Moon, where we will see the returns in a decade, not in a century.

The returns on development of the Moon and HEO industry will be in the Trillions, easily enough to then throw a few tens of Billions at Mars.

Then use what we learn on the Moon to reproduce that on Mars and some asteroids.

Maybe by that time we will have working fusion. We need fusion to go beyond the inner asteroid belt.

 

[YetAnotherBob]

. . . Sea shipping works on freight rates under US$100 per ton between distant major ports. With extraordinary improvements we might manage freight rates between Mars and Earth of under US$1,000,000 per ton. . .

Most of the cost of shipping to Mars comes in just getting off Earth. Earth has a huge gravity well. The best estimates I have seen for a system to ship goods between Earth and Mars would use something like the Vasimir Engine coupled with solar arrays at Earth and at Mars. The arrays would power the engines at the beginning and at the end of the journey. Costs would likely be on the order of a thousand dollars per ton between planets. Cost at the Earth end to launch from Earth are themselves around two thousand dollars per kilogram, or two million dollars per ton at current prices, so Earth produced goods would be quite expensive on Mars. That's only if Starship works out as promised. A rare thing indeed.

Costs to launch from the Moon using electromagnetic catapults, which have already been designed and work as well as any other rail gun, are on the order of a couple of dollars per ton.

So the most likely scenario is a three-way trade, where Mars supplies nitrogen based food stuffs that can be easily dried to the Moon. There is a twenty-six month window for that. The Moon meanwhile has a large industrial base that supplies Mars with precision hardware on the same time frame. Items that cannot be supplied by the Moon, very high value items of little weight, will be supplied by the Earth. The Moon will sling cargoes down to the Earth regularly.

One of Earths biggest exports will be people. But it will never be enough to impact the population of Earth in any measurable way. It was the same way with the settlement of the United States. No European nation saw it's population seriously decline by emigration to the US. The Irish probably came closest after the potato famine. But it was never more than a few thousand a month. For most of that time, it was a few hundred a month.

Mars will be the same. I don't expect to live to see Mr. Musk's Million Martians in my lifetime. Maybe by 2100. But not by 2030. Even his Thousand Starship Fleet wouldn't be enough. He was hoping for three hundred people per ship. It looks more like he might get thirty.

I also don't expect to see a thousand in a Great Fleet. Maybe twenty. Maybe.

So a Mars colony with a couple thousand people by 2030 or 2040. More than that would demand some great technical breakthrough.

 

[Jackie Cox]

I really don't think the Americas are a good template for Mars. There's just no comparison. Europeans didn't colonize the Americas. They conquered the humans who had already colonized the Americas thousands of years earlier. The Europeans were just moving in to a section of Earth that they hadn't known about before.

Once we colonize the other 2/3 of our planet, the alien lands under the seas, then we might have the skills to colonize other planets. And those lands are close by, with easy to convert air and water, normal gravity. Easy! And lots of close by mineral resources. So where are the colonies?

 

[Jackie Cox]

The suggestion that humans will soon set up bustling, long-lasting colonies on Mars is something many of us take for granted. What this lofty vision fails to appreciate, however, are the monumental—if not intractable—challenges awaiting colonists who want to permanently live on Mars. Unless we radically adapt our brains and bodies to the harsh Martian environment (become cyborgs), the Red Planet will forever remain off limits to humans.

Mars is the closest thing we have to Earth in the entire solar system, and that’s not saying much.

The Red Planet is a cold, dead place, with an atmosphere about 100 times thinner than Earth’s. The paltry amount of air that does exist on Mars is primarily composed of noxious carbon dioxide, which does little to protect the surface from the Sun’s harmful rays. Air pressure on Mars is very low; at 600 Pascals, it’s only about 0.6 percent that of Earth. You might as well be exposed to the vacuum of space, resulting in a severe form of the bends—including ruptured lungs, dangerously swollen skin and body tissue, and ultimately death. The thin atmosphere also means that heat cannot be retained at the surface. The average temperature on Mars is -81 degrees Fahrenheit (-63 degrees Celsius), with temperatures dropping as low as -195 degrees F (-126 degrees C). By contrast, the coldest temperature ever recorded on Earth was at Vostok Station in Antarctica, at -128 degrees F (-89 degrees C) on June 23, 1982. Once temperatures get below the -40 degrees F/C mark, people who aren’t properly dressed for the occasion can expect hypothermia to set in within about five to seven minutes.

The notion that we’ll soon set up colonies inhabited by hundreds or thousands of people is pure nonsense.
Mars also has less mass than is typically appreciated. Gravity on the Red Planet is 0.375 that of Earth’s, which means a 180-pound person on Earth would weigh a scant 68 pounds on Mars. While that might sound appealing, this low-gravity environment would likely wreak havoc to human health in the long term, and possibly have negative impacts on human fertility.

Yet despite these and a plethora of other issues, there’s this popular idea floating around that we’ll soon be able to set up colonies on Mars with ease. SpaceX CEO Elon Musk is projecting colonies on Mars as early as the 2050s, while astrobiologist Lewis Darnell, a professor at the University of Westminster, has offered a more modest estimate, saying it’ll be about 50 to 100 years before “substantial numbers of people have moved to Mars to live in self-sustaining towns.” The United Arab Emirates is aiming to build a Martian city of 600,000 occupants by 2117, in one of the more ambitious visions of the future.

Even if all these obvious problems are somehow solved, who in their right mind (after the initial kick of living on another planet wears off) would actually wanna live in such a hellish place?

And what about the critically important microbiome?

Apparently, many people have forgotten the Biosphere I and Biosphere II projects in the Arizona desert designed to test a completely enclosed, self-sustaining environment for long space flights. After ten of millions of dollars spent, both were miserable failures.

 

[YetAnotherBob]

b
Biosphere I was not a failure. It is the Earth, in it's entirety. So far it's lasted for six thousand to three and a half billion years, depending on who you believe.

Biosphere II did fail It tried to pack too much of rather variable environments in to a single facility. They also forgot to account for the pizza.

 

[Jackie Cox]

Most of the cost of shipping to Mars comes in just getting off Earth. Earth has a huge gravity well. The best estimates I have seen for a system to ship goods between Earth and Mars would use something like the Vasimir Engine coupled with solar arrays at Earth and at Mars. The arrays would power the engines at the beginning and at the end of the journey. Costs would likely be on the order of a thousand dollars per ton between planets. Cost at the Earth end to launch from Earth are themselves around two thousand dollars per kilogram, or two million dollars per ton at current prices, so Earth produced goods would be quite expensive on Mars. That's only if Starship works out as promised. A rare thing indeed.

Costs to launch from the Moon using electromagnetic catapults, which have already been designed and work as well as any other rail gun, are on the order of a couple of dollars per ton.

So the most likely scenario is a three-way trade, where Mars supplies nitrogen based food stuffs that can be easily dried to the Moon. There is a twenty-six month window for that. The Moon meanwhile has a large industrial base that supplies Mars with precision hardware on the same time frame. Items that cannot be supplied by the Moon, very high value items of little weight, will be supplied by the Earth. The Moon will sling cargoes down to the Earth regularly.

One of Earths biggest exports will be people. But it will never be enough to impact the population of Earth in any measurable way. It was the same way with the settlement of the United States. No European nation saw it's population seriously decline by emigration to the US. The Irish probably came closest after the potato famine. But it was never more than a few thousand a month. For most of that time, it was a few hundred a month.

Mars will be the same. I don't expect to live to see Mr. Musk's Million Martians in my lifetime. Maybe by 2100. But not by 2030. Even his Thousand Starship Fleet wouldn't be enough. He was hoping for three hundred people per ship. It looks more like he might get thirty.

I also don't expect to see a thousand in a Great Fleet. Maybe twenty. Maybe.

So a Mars colony with a couple thousand people by 2030 or 2040. More than that would demand some great technical breakthrough.

earths mineral resources derived from a living earth From petrochemicals to ores, even diamonds are pure carbon.
fed by earths volcanoes and hydrogen oxygen seas we are a wonderful creation.

Mars, without a viable gravitational field it’s unlikely we will find minerals to smelt metals or refine petrochemicals

Mars a popular Science a Fiction Theme before we really knew the extent of our galaxies or what they are like or made of.
Following a bit of exploration whereby we can sort of model atmospheres, climate, geophysical shapes and colors, but we have yet to drill cores to determine mineral substance. however with the data we have, If we compare galactic bodies, a more likely effort to colonize another planet might likely be the outer moons of Jupiter.

from my perspective the clamor about Mars exploration, so-called colonization is a tremendously expensive venture without ant viable opportunity to profit from the venture.

<<Political content removed by moderator>>

 

[YetAnotherBob]

earths mineral resources derived from a living earth From petrochemicals to ores, even diamonds are pure carbon.
fed by earths volcanoes and hydrogen oxygen seas we are a wonderful creation.

Mars, without a viable gravitational field it’s unlikely we will find minerals to smelt metals or refine petrochemicals

Mars a popular Science a Fiction Theme before we really knew the extent of our galaxies or what they are like or made of.
Following a bit of exploration whereby we can sort of model atmospheres, climate, geophysical shapes and colors, but we have yet to drill cores to determine mineral substance. however with the data we have, If we compare galactic bodies, a more likely effort to colonize another planet might likely be the outer moons of Jupiter.

from my perspective the clamor about Mars exploration, so-called colonization is a tremendously expensive venture without ant viable opportunity to profit from the venture.

<<Political content removed by moderator>>

Mars and the Moon too have the same minierals that Earth has. We have satellites that have measured them from orbit. Lasers are wonderful things for some uses. Finding mineral deposits is one of them. We already know where do dig for specific minerals on both worlds. (Yes, both worlds. The Moon is actually a double planet with Earth.)

It's apparent that you don't like Mr. Musk. OK. I don't know the man. He may be a saint or he may be worse than you describe. He's probably somewhere in between.

Earths mineral resources are identical to those on the Moon, minus the iron in many locations. Though there are cubic kilometers of it from asteroid and meteor strikes. The Moon is like the Earth but without the molten iron core.

The current explanation for that is a collision with a protoplanet four and a half billion years ago that threw off a great deal of the crust that then solidified in orbit as the moon.

Mars is almost the same mineralogically to the Earth.

One real difference is the ore deposits that were formed by bacteria on Earth several billion years ago. Most of our iron comes from that. The bulk of Earth's iron is several thousand miles under our feet. There is still enough on the surface though for our industry.

Mars lacks those iron ore deposits. It does have though a great deal of iron oxide on the surface. That's the famous red color of Mars.

For other minerals, hydrocarbons are not biological in origin. That is a myth that has been perpetuated for several generations. No, most oil doen'st come from dinosaurs. It's actually the result of carbon partially burned in a hydrogen atmosphere. There are lakes, even perhaps oceans of it on Titan.

There are deposits of petroleum on Mars as well. There are also asteroids with more oil that Saudi Arabia. It's how you find most of the carbon in space.

Though petroleum isn't that useful on Mars.

On Earth we can use petroleum as a convenient power source because terrestrial plants have been dumping oxygen into the atmosphere for a long long time. It's build up to the point where a quarter of our atmosphere is oxygen. Mars doesn't have that. So to burn say gasoline, you have to bring along all the oxygen.

That increases fuel weight and volume by several times. It tips the balance in selecting the best power source.

The other primary use of hydrocarbons is for making plastics.

But CO2 and water can also be the basis for plastics. Both of those are found almost everywhere on Mars. So I don't see the need for hydrocarbons there. It's cheaper to suck in air than it is to drill for oil.

But like it or not, Space is being used and is becoming more important to life here on Earth. We are expanding. Someone will go to Mars and stay. Someone else will go to the Moon and make a large fortune. If not an American, the a Chinese. they've already said they intend to do it.

We can compete or we can surrender. There are only two choices.

I don't understand the desire to surrender.

 

[egribble]

Actually,the correct answer to 'Should we colonize the Moon, Mars the Asteroids or some space based habitat' is yes, all of the above.

The Moon is the obvious first choice. It has a lot of material resources, it is also closer than any other destination. Developing the Moon will teach us what we need to survive long term in space.

But the Moon has very little nitrogen. Nitrogen is vital to life. So the Moon will never be able to sustain itself without constant re-supply from Earth.

Mars has everything the Moon has, but it also has nitrogen. Limited supplies, yes, but there are millions of tons of nitrogen there that only needs an air compressor to get it. So Mars can survive without Earth.

Mars however will never have a 'shirtsleeve' environment. It hasn't enough air. Without some powerful technology that we can calculate, but can't currently construct, it never will.

But that's OK to an indoor civilization. Mars hasn't much atmosphere. It has enough though to support a few Billion people. It also has much easier access to space. It takes about a tenth the rocket to reach orbit around Mars than it takes around Earth.

New York is almost an indoor civilization. So is Tokyo and Hong Kong. So too is Singapore. Each of them would just need some sealed walkways between buildings to be a good analogue to Mars in all but the industrial sector.

What we shouldn't do is spend hundreds of billions to build up Mars quickly. Spend that on the Moon, where we will see the returns in a decade, not in a century.

The returns on development of the Moon and HEO industry will be in the Trillions, easily enough to then throw a few tens of Billions at Mars.

Then use what we learn on the Moon to reproduce that on Mars and some asteroids.

Maybe by that time we will have working fusion. We need fusion to go beyond the inner asteroid belt.

We should not forget the Gerald O'neill space colony concept as well. The view here was that it made less sense settling on a planetary surface than to build space colonies that negated the need to get out of a planetary gravity well. It was suggested resources from the moon and low gravity asteroids be used for construction. All very futuristic but made sense. I suspect, once mankind makes a real move off planet, we will move in all directions.

 

[egribble]

Mars and the Moon too have the same minierals that Earth has. We have satellites that have measured them from orbit. Lasers are wonderful things for some uses. Finding mineral deposits is one of them. We already know where do dig for specific minerals on both worlds. (Yes, both worlds. The Moon is actually a double planet with Earth.)

It's apparent that you don't like Mr. Musk. OK. I don't know the man. He may be a saint or he may be worse than you describe. He's probably somewhere in between.

Earths mineral resources are identical to those on the Moon, minus the iron in many locations. Though there are cubic kilometers of it from asteroid and meteor strikes. The Moon is like the Earth but without the molten iron core.

The current explanation for that is a collision with a protoplanet four and a half billion years ago that threw off a great deal of the crust that then solidified in orbit as the moon.

Mars is almost the same mineralogically to the Earth.

One real difference is the ore deposits that were formed by bacteria on Earth several billion years ago. Most of our iron comes from that. The bulk of Earth's iron is several thousand miles under our feet. There is still enough on the surface though for our industry.

Mars lacks those iron ore deposits. It does have though a great deal of iron oxide on the surface. That's the famous red color of Mars.

For other minerals, hydrocarbons are not biological in origin. That is a myth that has been perpetuated for several generations. No, most oil doen'st come from dinosaurs. It's actually the result of carbon partially burned in a hydrogen atmosphere. There are lakes, even perhaps oceans of it on Titan.

There are deposits of petroleum on Mars as well. There are also asteroids with more oil that Saudi Arabia. It's how you find most of the carbon in space.

Though petroleum isn't that useful on Mars.

On Earth we can use petroleum as a convenient power source because terrestrial plants have been dumping oxygen into the atmosphere for a long long time. It's build up to the point where a quarter of our atmosphere is oxygen. Mars doesn't have that. So to burn say gasoline, you have to bring along all the oxygen.

That increases fuel weight and volume by several times. It tips the balance in selecting the best power source.

The other primary use of hydrocarbons is for making plastics.

But CO2 and water can also be the basis for plastics. Both of those are found almost everywhere on Mars. So I don't see the need for hydrocarbons there. It's cheaper to suck in air than it is to drill for oil.

But like it or not, Space is being used and is becoming more important to life here on Earth. We are expanding. Someone will go to Mars and stay. Someone else will go to the Moon and make a large fortune. If not an American, the a Chinese. they've already said they intend to do it.

We can compete or we can surrender. There are only two choices.

I don't understand the desire to surrender.

I personally believe Mars is a step too far at present (two and a bit year launch window, 4 month journey, deeper gravity well then moon, radiation concerns etc). However Elon believes he can do it. The moon has surface He3 and concentrated deposits of rare earth metals which may be profitable to mine one day (a launch system like starship will bring down costs). Also in situ resource utilisation (using lunar ice for fuel production) will help reduce transport costs. Lunar science etc, there are many reasons to go to the moon. I do not believe using the expensive SLS and assembling stuff in lunar orbit for a trip to Mars is practical. I do not believe NASA's talk about going to Mars is realistic, maybe just talk to keep congress happy. They do not actually seem to have formulated any realistic plan.

 

[Catastrophe]

YAB posted: "The Moon is actually a double planet with Earth.)"

"The Moon is the Earth's nearest neighbor in space. For this reason, the Earth-Moon system is sometimes considered a double planet. It is the center of the earth-Moon system, rather than the center of the Earth itself, that describes an elliptical orbit around the sun in accordance with Kepler's laws ." Wiki

Surely this is always the case. It is the centre of the system which obeys Kepler's Laws, however small the moon.

I have seen another definition when both bodies are considered to be of planetary mass.

The barycentre of the Earth-Moon system is about 0.75 Earth radius from Earth centre. Pluto and Charon are sometimes considered a binary system because their barycenter does not lie within either body. Wiki

My opinion would be when the barycentre does not lie within either body as this is a specific condition. The planetary body suggestion could be quantified by a mass ratio, of course.

So what is the correct definition (if there is one at all?).

Should a new thread be started for this?

 

[dfjchem721]

Cat, the "correct", or scientifically "dictated" definition is made by the International Astronomical Union (IAU). They are the ones who define planets and moons, etc, and they are the ones who down-graded Pluto to dwarf planet status.

Clearly the earth and moon are not a binary planetary system. One imagines that the IAU would strenuously oppose such a designation - there are rules involved here! But people have various opinions. Many were not amused when Pluto was down-graded, and some are still not!

However, one could make the argument that Pluto and Charon is a binary dwarf system based on your barycenter concept. But Pluto has other moons, and Charon does not have any moons, so one supposes that this eliminates Charon as a dwarf planet and keeps it as a moon.

Just now seeing that the barycenter of the sun and Jupiter lies outside the solar sphere, giving support to those who say we live in a binary yellow/brown dwarf system.

wiki:

"Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined—this is so massive that its barycenter with the Sun lies above the Sun's surface at 1.068 solar radii from the Sun's center."

 

[Catastrophe]

Granted that I respect anyone's right to hold their own opinion (especiallythat of yourself), may I ask where you stand on the Pluto question? Or is it not the sort of question one asks in public?
I am a bit surprised about the Charon verdict. I would have thought that any system would have a barycentre, irrespective of the n-body problem. Perhaps just too difficult to work out. I suppose then one should include the smallest piece of junk we sometimes designate with the title 'satelliteI'. And yes, I was aware of the event of 2006!!!/

 

[dfjchem721]

The "Pluto Question".

Sounds almost like a cosmic spat. Are you a planet snob of sorts?!

Actually, if I was close to the planetary aspects for a long time, would probably be whining about the down-grade. As you say, everyone has a right to an opinion.

Considering its extreme inclination off the ecliptic, the fact that asteroids have been found with moons, and its closer approximation with the scattered disc, with lots of other objects just like it and some almost as big, the down-grade seems appropriate.

The data from New Horizons showing an amazingly varied landscape, and the parting shot from behind revealing a glowing atmosphere lit up by the sun, well, it does seem to look every bit like a planet. One could make a strong case either way.

Science, however, will always go with the IAU. And yes, they have a lot of snobs too!

 

[Catastrophe]

"Sounds almost like a cosmic spat. Are you a planet snob of sorts?! "

Yes, of course. I don't support any move to describe the smaller dust particles (notice I did not say smallest) orbiting the Sun as nanoasteroids let alone nanoplanets. As I am against calling the bits of rock circling Mars - moons, other than on historical grounds. OK I will take my tongue out of my cheek.

Of course I am aware of that 'parting shot'. You have the inner rocky planets, the gas giants (subdivide U and N if you will) and you have a dwarf planet which just happened to be discovered decades before its near relatives. So elevate Eris and all the rest - for what - an emotive description of one large lump of rock which just happened to be photographed by an exiting probe.

As a physical chemist you know far better than I that gas or liquid phases depend on T and P which depend on how far from the Sun the bodies are. (Ahh - those happy distant memories of PV=nRT) Any 'atmosphere' is clearly time dependant including factors like travelling around the Soar System, time to lose more volatile gases.
If Pluto 'decides' to take a 'summer holiday nearer the Sun, and loses that famed atmosphere, will 'they' still call it a Planet?

I am governed by General Semantics (Korzybski) whose catchphrase IYes I know that he didn't actually originate it) was the map is not the territory. Words are cheap. There are all sorts of reasons why one group of people might favour one particular selection of words over another. I select those words which best enable me to understand subjects in which I am interested. Pluto is not a gas giant. It is an interloper (vide your mention of orbital inclination). I am not going to alter my opinion of what a planet should be because someone might wish to retain an historical description. I have no one to account to but myself. I do not wish to publish. To me Pluto is an interloper which does not fit the logical planet classification - inner rocky / gas giant. Ergo it is a lump of rock which has caused more fuss than that with which I would dignify it.

The relevance of all this to Mars colonies are a fantasy is that whether we call some body a planet, a dwarf planet, an asteroid or what you will, the cutting edge remains: can it be terraformed or only colonised? If the latter, are there any reasons why we should colonise it?

When (if) Korztbski were ever to be disproved, I shall have to change my criteria of description. Not in my lifetime.

 

[dfjchem721]

To me Pluto is an interloper which does not fit the logical planet classification - inner rocky / gas giant. Ergo it is a lump of rock which has caused more fuss than that with which I would dignify it.

That was quite a treatment - from nanoplanets to gas giants.

I would only like to add something about binary planets, and why Pluto and Charon should not be considered as such. Binaries, typically stars, form independently of each other. Therefore the moon, derived from an impact of earth with some other body, certainly doesn't qualify. And Charon, while we do not know how it was formed, may be too small to even consider it a dwarf planet, so it is relegated to a moon.

Still, it beats being a nanoplanet. Not enough names for all of those......

 

[Catastrophe]

Since just about every planet in our Solar System has been hit by something large enough to make a major difference perhaps we should call them all interlopers:
Mercury - mantle lost to the Sun? Exceptional metal core.
Venus - rotates backwards
Earth - unusual Moon
Mars - have I missed something?
Jupiter - minor comet impacts* - but actually observed
Saturn - largest ring system
Uranus - axis changed about 90 derees
Neptune - spins very rapidly
You can probably fill in some / all blanks.
Most / all from Late Heavy Bombardment (except Jupiter).

 

[dfjchem721]

Since just about every planet in our Solar System has been hit by something large enough to make a major difference perhaps we should call them all interlopers:

The one thing that gets me is, of the four rocky planets, only earth has a natural moon. Those of Mars I believe are captured nanoplanets, and of course Mercury and Venus have no moons.

If earth's moon was formed by one or more collisions, why didn't more of them form moons in much the same fashion? I have heard suggestions about Mercury and Venus being too close to the sun, and the gravity variance precluded any moon formation too close in, but am not so sure this is a good reason.

So where are all the "big" moons to the other three rocky inner interlopers?! Just one out of four seems a bit odd.

 

[Catastrophe]

The one thing that gets me is, of the four rocky planets, only earth has a natural moon. Those of Mars I believe are captured nanoplanets, and of course Mercury and Venus have no moons.

If earth's moon was formed by one or more collisions, why didn't more of them form moons in much the same fashion? I have heard suggestions about Mercury and Venus being too close to the sun, and the gravity variance precluded any moon formation too close in, but am not so sure this is a good reason.

So where are all the "big" moons to the other three rocky inner interlopers?! Just one out of four seems a bit odd.

"Just one out of four seems a bit odd."
Is it not that Earth is the odd one being hit by just the "right" size object and both "surviving"?

 

[YetAnotherBob]

We should not forget the Gerald O'neill space colony concept as well. The view here was that it made less sense settling on a planetary surface than to build space colonies that negated the need to get out of a planetary gravity well. It was suggested resources from the moon and low gravity asteroids be used for construction. All very futuristic but made sense. I suspect, once mankind makes a real move off planet, we will move in all directions.

Practically speaking, any HEO large satellite will be a modified O'Niel colony. The actual designs in O'Niel's book won't be used They had large glass windows. Interstellar dust would shatter those. But there are work-arounds.

So I do agree that there will be space colonies in orbit in the next twenty years or so.

Most of the Moon's agriculture will likely be grown on things architecturally similar to O'Neil's designs. They won't be precisely what was pictured in the book however.

Those designs once adequate will be what the Asteroid Miners actually live in.