Quote from H-G Branzell

bang99,

Let a fantasy be a fantasy. All space adventure movies are fantasies. Some lay claim to be realistic but in fact they are pseudo-realistic and may implant false ideas in peoples mind about the possibilities of space travel and extraterrestial colonization.

Ok, H.-G, I'm fine with that.

When you mentioned this Mars movie with Val Kilmer (with I like very much, he also was in "The Saint", the Cold Fusion Movie

I had a terrible flashback, 'cause I remembered the year 2000 when "Mission to Mars" and "Red Planet" were in the cinema and how awful and dissapointing these two movies were in my opinion.

I posted my opinion in affect/ shortcut reaction

Elon Musk's / SpaceX vision of colonisation of Mars and then using Mars as a base to go the Asteroid Belt, starting in 2022 (I know, Elon's milestone s are "ambitiously" are in the timewindow that I hope to be still alive.

BTW: Have you seen the TV-Series "The Expanse" ?

Long before humans successfully colonize Mars, the abundant Earth bacteria, attached to the humans that will die there, will begin successful colonization. This is a great fear of NASA, that the Earth micro life will contaminate Mars before indigenous Mars life can be found (if any). Spacecraft and probes can be quite well, if not perfectly sterilized, but not so for humans.

Think of it as colon-ization...

The moral dilemma that humanity must face is: if we find native microbial life on Mars, do we have the right to bombard the planet with cometary and asteroidal ice to begin the process terraforming the planet (to some degree), possibly killing the native species? The bombardment must begin fairly soon in order to have success in this venture before humans can safely move in, after which it may be too dangerous to continue the delivery of water and oxygen in the quantity neccesary to make a difference.

I personally don't see a moral conundrum in the possibility of killing a native species of microbe on Mars, provided we try to learn about it before such a thing happens. It is a feature/bug of the universe that when you go off to somewhere else you bring microbes with you, and with them come the possibility of catastrophic replacement.

The moral dimension for me would depend upon how sentient the creatures are. If there were small rodents or something, it would feel a little differently (maybe?). If they were (hypothetically speaking) bona fide martians with homes and so on, that would tip the scales for me against it.

There is of course the danger going the other way: we could bring back some martian bug that kills all algae or something, and then watch the food chain collapse.

You don't have a problem with wiping out the only extraterrestrial life ever found (if there is any)?

I think it could be a bad precedent.

Humanifest Destiny? (Human infest destiny).

If it were somehow related to Earth life, (Mars seeded Earth, Earth already seeded Mars, or some evidence of galactic panspermia), then I can see more shades of grey in the thinking that Mars life might be expendable in the best interests of humanity. But it still seems harsh.

My thought is that there are already dozens (hundreds?) of known Earth-like planets in orbit around nearby stars. The likelihood in my mind that there is extraterrestrial life of some rudimentary form seems close to 100 percent (which is different than saying that it is close enough for examination anytime soon).

How many stars are there in the visible universe? Some appreciable fraction of them surely have life on planets orbiting them. The numbers we're talking about imply to my mind that life-bearing planets in the universe are as abundant as microbes on this planet.

A suitable analogy for the moral dimension to this question is exploration of a new continent or newly-discovered island on Earth. I would not argue that we should not go there out of fear of disrupting the native species unless the potential cost was high indeed.

We know quite well the consequences of invading "new" continents and islands on Earth. The original inhabitants far too often end up in museums and diaries of explorers as examples of what once was there.

Quote from Paradigmnoia

We know quite well the consequences of invading "new" continents and islands on Earth. The original inhabitants far too often end up in museums and diRies of explorers as examples of what once was there.

Yes, I'm quite aware of that danger, and it has been in my mind this whole time. But I think it would be a futile argument to argue against the idea that people should have explored (or will explore) other islands on Earth. But that is also why I introduced the part about a risk assessment of harming life with any amount of sentience.

Quote from Paradigmnoia

This is a great fear of NASA, that the Earth micro life will contaminate Mars before indigenous Mars life can be found (if any). Spacecraft and probes can be quite well, if not perfectly sterilized, but not so for humans.

This is regrettable but I see no way to avoid the problem. I read a long technical article about the steps they are taking now to sterilize robot explorers. It included an interview with the woman at NASA who is in charge of that. She says even now we have probably sent millions of bacteria to Mars despite her best efforts, and many of them probably survived. They survive simulated space journeys in vacuum with radiation.

Quote from Paradigmnoia

if we find native microbial life on Mars, do we have the right to bombard the planet with cometary and asteroidal ice to begin the process terraforming the planet (to some degree), possibly killing the native species?

That is a difficult moral question.

Quote from Paradigmnoia

The bombardment must begin fairly soon in order to have success in this venture before humans can safely move in, after which it may be too dangerous to continue the delivery of water and oxygen in the quantity neccesary to make a difference.

Nope. There would be no danger to human inhabitants from bombarding Mars with ice. You just have to cut the ice into small pieces so they melt or evaporate before hitting the ground. The earth is bombarded with ice comets every day, but it seldom reaches the ground or causes harm. Rocks (asteroids) on the other hand, are more dangerous. The sometimes reach the ground as meteorites. Of course a very large chunk of ice would be catastrophic!

Quote from JedRothwell

Nope. There would be no danger to human inhabitants from bombarding Mars with ice. You just have to cut the ice into small pieces so they melt or evaporate before hitting the ground. The earth is bombarded with ice comets every day, but it seldom reaches the ground or causes harm. Rocks (asteroids) on the other hand, are more dangerous. The sometimes reach the ground as meteorites. Of course a very large chunk of ice would be catastrophic!

Easier just to lob big ones. They might explode in the atmosphere nicely if they are just the right size, but some are bound to hit the surface when working out the most effective size to send.

Maybe set aside a handy (very large) area for raining down large ice (or metal) chunks.

Is there an estimate of the cost for lobbing one or more ice comets on a trajectory to hit Mars?

Quote from Eric Walker

Is there an estimate of the cost for lobbing one or more ice comets on a trajectory to hit Mars?

Not cheap at present. Presumably with space-rated LENR one could just heat holes in an interplanetary iceberg and propel it towards a target with the ejected steam.

I'm thinking it would be prohibitively expensive without something like LENR (and even quite expensive with LENR). Hard to even come up with a ballpark number for the cost.

Quote from Paradigmnoia

Easier just to lob big ones. They might explode in the atmosphere nicely if they are just the right size, but some are bound to hit the surface when working out the most effective size to send.

I do not think "easy" or "hard" are applicable. On the scale that is needed, the job can only be done by robots in deep space. I think they will have to be self-replicating robots, built locally from materials on site, and powered locally, because it might take millions of them. In that scenario, the blocks of ice could be cut into any size you like. It would have no impact on the cost of the project, or the duration. If it takes an extra million robots it would make no difference because you need a technology where an extra million self-replicated robots cost virtually nothing.

The project might require some human being on site to supervise or trouble-shoot. I cannot predict how well AI and self-replication will advance, so I cannot predict whether people will be need or not. Not many people will be needed, in any case. I suppose it would prohibitively expensive if it took thousands of people living in deep space. I guess that depends on how many people live on Mars, and how willing they are to pay taxes for terraforming. People on Earth sure aren't going to pay for it!

Quote from Eric Walker

Is there an estimate of the cost in today's terms that would be needed to lob one or more ice comets on a trajectory to hit Mars?

Gazzillions of dollars! More than the whole GDP of the USA. This is a bit like asking how much money my desktop computer would cost in 1965. My computer tells me it operates at 2.93 GHz, it has 14.0 GB of RAM and 1 TB sold state hard disk. I have a computer textbook from the 1960s and skimming through it . . . I think the fastest computer was the IBM 360 System 50, 500 nanoseconds, or 2 MHz clock. The biggest one had about 800 MB of disk. So I have on the order of 1200 times more disk space and 1500 times more speed (ignoring the fact that my computer has multiple CPUs). Make it a factor of 1300. Okay, the 360 was introduced in 1964 and it began to have an impact in 1965, which was the dawn of the modern computer era. Total sales of all computers that year were 5,610 computers worth $1.8 billion ($14.2 billion inflation adjusted). 5,350 of them were mainframes. See:

https://www.bls.gov/opub/mlr/1986/09/art2full.pdf

The biggest ones were 1300 times smaller than mine. Many were smaller; on the order of 10,000 times smaller. (The ones I personally programmed back then were much smaller!) Assuming they were all the biggest models, my computer would cost roughly 27% of all the computers sold in 1965, or ~$3.8 billion in current dollars. I think ~60% of all computers and $10 billion would be more realistic. A cost reduction by a factor of ~10 million. It is a very rough estimate. Of course you could not build such a machine back then, and even if you did it would not have many of the capabilities mine has, such as voice input or showing hi-res videos. Look at the specifications for supercomputers of that era and you will see they were tiny compared to mine.

The point is, computer technology has changed a great deal. The most important technologies to accomplishing this Mars project would be robots, artificial intelligence, and machines that make themselves, which is to say general purpose machines that can make anything, sort of like 3D printers. These have just been invented recently. So far they can only make little plastic things and prototypes, but they are improving rapidly. As everyone knows, robots and AI are also improving rapidly, with the near-term introduction of things like self-driving automobiles.

I expect this project will not even begin for another 50 years. I expect progress in these three technologies over the next 50 years will be as dramatic as progress in computers has been the last 50 years. These fields are mostly computer science, and I do not see any reason to think progress will slow down or some limit will be reached. So, to make a long story short, I expect that robots capable of doing this will cost little or nothing 50 years from now. They will be about 10 million times cheaper than our best robots, and far more capable, just as my desktop computer is 10 million times cheaper and has better features more suited to my purposes (such as voice input) compared to its equivalent 50 years ago. If these robots are locally self replicating without human intervention, they will literally cost nothing. You will dispatch a few dozen to the site and some years later you will have millions at work, at no cost or effort by any person.

I do not see why such self-replicating machine would be impossible. They would be enormously valuable, and technology is already heading in that direction, so I suppose they are inevitable.

I think the cost of a computer has fallen by a factor of roughly 10 million since the 1960s. The cost of some components has fallen a great deal more than that. Since 1960, the cost of computer RAM and disk storage have fallen by 8 orders of magnitude. See pp. 10 and 11:

http://lenr-canr.org/acrobat/RothwellJcoldfusionb.pdf

I see no reason why the cost of robots and other computer technology will not fall by similar margins in the next 50 years. Or, if the cost does not fall that much, the capacity and capabilities will improve to a similar extent. Computers are mainly made of plastic and sand, so materials are not a limitation or an issue. The total starting cost of the raw materials in a $1000 desktop is probably a few dollars, for oil (plastic), iron (metal parts) and sand (silicon). $998 is value added by those clever people at Intel and Microsoft.

Quote from JedRothwell

machines that make themselves, which is to say general purpose machines that can make anything, sort of like 3D printers. These have just been invented recently.

Incidentally, the plot of Horizon Zero Dawn, a PS4 video game, was that self-replicating military robots started to multiply without end as a result of a system failure. They took over the world and (in time) snuffed out the remnants of humanity. The only way for humanity to "survive" was to create underground bunkers where people would be hatched in vitro hundreds of years later, after the robot plague had wound down. They were then to be educated with a system put in place for this purpose so that they could continue civilization's legacy. (Plot twist: the education subsystem failed, and the later-hatched people ended up reverting to a hunter-gatherer society. Second plot twist: the robot plague did not fully wind down.)

Quote from Eric Walker

I'm thinking it would be prohibitively expensive without something like LENR (and even quite expensive with LENR). Hard to even come up with a ballpark number for the cost.

I think solar energy might be better, although that is pretty thin in the Oort cloud where the water is. Perhaps giant Mylar mirrors would be needed to concentrate the sunlight.

Anyway, here is a ballpark number --

Mars probably had an ocean covering 1/3rd of the surface, called the Borealis Ocean. The volume was ~6 million km^2. It is on the same scale as the Mediterranean Sea, 3.7 million km^2. I do not know if we would want to put it all back, and cover a third of the planet, but suppose we did.

Suppose the plan is to do this over 100 years, or 3.154e+9 seconds. That would call for delivering 0.0019 km^2 per second, or 1.9 million tons. Compare this to oil production today. That is 96 million barrels per day, or 176,652 L/s. Or 176 tons. So it would be roughly 11,000 times larger than today's oil industry. That is not an unthinkable scale, and the energy and materials it consumed would be within our grasp with self-replicating robots. Or, compare it to water consumption in Atlanta, GA, which is 1,202 million gallons/day. That's 4.5 million tons per day, or 52 tons/second. So we are talking about the waterworks in 37,000 large cities. U.S. consumption is roughly 4 trillion tons/year, or 127,000 tons/second, so this would call for about 10 times more waterworks than the entire U.S. has. Not an unthinkable amount of equipment. Water is cheap, which means we can easily afford the equipment and energy it takes us to pump, purify, store and deliver water today. I think 10 times the present waterworks is an overestimate. Melting the ice would mostly be done with mirrors and sunlight. It would take about 10 times the number of pumps and purifiers that we have today in the U.S., but you do not need reservoirs, pipelines under the street or water meters, so much less equipment and infrastructure overall. Say, 2 times as much as U.S. waterworks? In 50 or 100 years, the people on Mars could afford a project on that scale.

I do not know how small you would have to make the chunks of ice to ensure they would all safely melt long before they reached the ground, but suppose it is 1 ton (1 cubic meter). You have to launch 1.9 million per second, or 114 million per minute. I suppose the best way to do this is to deploy equipment to 114 million comets in the Oort cloud, and have the machinery melt the ice, purify the water, put it into 1 m^2 containers (like a giant ice tray), and let it freeze. Take out the 1 m^2 chunks and launch one toward Mars every minute. I would send them off 1 per minute to keep them from whacking together and going off course. After every 10,000 launches (160 hours) you might need to send a small rocket along with the chunks to nudge them for course corrections or if they get tangled up together. 11,000 of these rockets would reach Mars every minute, but they would change course the last day to avoid crashing into it, and they might be collected and sent back to the comets. The rockets would use water as propellant, and they would not need much, because they are mostly falling along with the chunks of ice.

The equipment needed to produce this much frozen water would be considerably less than 11,000 times our present oil drilling, refinery and transportation infrastructure because the water is much more easily accessed, easier to purify and process, and you only need to store about 1 day's worth. (I guess that is how long it would take to freeze.) As I said, I guess it is about 2 times the size of U.S. waterworks.

Once the ice is launched it may take months or years to reach Mars. I doubt there would be much work or expense riding herd on it, and it would cost nothing once it fell. It would have no visible impact. I doubt anyone would notice the mist in the stratosphere. As years passed you would see rainfall begin, and the ocean begin to fill in, but it would be a gradual process. Perhaps they will want to fracture some of the water and pump the oxygen into the atmosphere, and dump the hydrogen somewhere (the sun?).

Of course they might not want a third of the planet under water, and they might want to take longer than 100 years, so you might end with a project one-tenth the size of U.S. waterworks. The point is, the scale of it and the energy demand is not unthinkable by any means. It is not on a scale greater than infrastructure is today.