Posts Tagged ‘Comets’

Terraforming the Moon by Comet

December 31, 2016

In my last blog post, I discussed the passed in David A. Hardy’s book, Atlas of the Solar System, in which he described the possible methods which might be used in the future to transform Mercury, Venus, the Moon and Mars into worlds, where humans and other creatures could live in the open, instead of the enclosed environments they need now to protect them from the harsh conditions of space. In the case of Venus, comets would be used to increase the planet’s rotation from its current 224 Earth days to a terrestrial day, and give the planet water. Looking through YouTube, I found this video by Fraser Cain, in which he talks about using the same method to terraform the Moon, as suggested by the space scientist and SF writer, Gregory Benford. This is part of a series of videos on space and space colonisation. At the beginning of the video, he mentions a previous one about the terraforming of Venus.

The explanatory section on the YouTube page provides this transcript of his talk.

In our episode about terraforming Venus, we talked about cooling the planet with a giant sunshade, and then hand-wavingly bind up all that carbon dioxide.

We did the same with Mars, filling the atmosphere with greenhouse gasses to warm it up, and releasing the planet’s vast stores of C02 to thicken the atmosphere. Then just crash in a few comets worth of water and upgrade them to to a 3 star resort.

We’re pitching this as a new series on the Discovery Network, called “Flip My Planet – Canada”.

Now let’s turn our imagination towards another rockball that is really more of a fixer-upper: The Moon. I know, you never even thought of the Moon as a place that we could possibly terra-renovate. Go ahead and imagine with me all the possibilities of a verdant green and blue little world hanging in the night sky. Doesn’t that sound great?

So, what does it take? Do we tear it down and just use the orbital lot space? Should we raise it up and lay a new foundation? Or could we get away with a few coats of paint and adding an atrium on the backside?

Fortunately for me, scientist and sci-fi author Gregory “Planetary Makeover” Benford has already done the math.

Let’s take a look at what we’d need to get the Moon habitable. For starters, the fact that the Moon is so close to Earth is a huge advantage. This is like living on the same block as a Home Depot, and we won’t have to travel far to get supplies and equipment to and from our project.

We’re going to need an atmosphere thick enough to breathe and trap in the Sun’s heat. This takes wild comet capture and harvest, tear them apart and smash them into the Moon.

Benford notes that you probably want be careful not to let an entire comet collide with the Moon because it might spray your primary investment home with debris and do a little damage to the resale value, or potentially annoy your tenants.

This could get bad enough that we’d have to terraform Earth to get it livable again, and you’d need to bring in Mike Holmes to publicly shame us and put our primary residence back in order.

After you’d splattered a few comets on the Moon, it would have an atmosphere almost immediately. The transfer of momentum from the comet chunks would get the Moon rotating more rapidly.

If you invest a little more in your planning stage, you could get the Moon spinning once every 24 hours, and even tilt its axis to get seasons. Benford estimates that we’d need 100 Halley’s mass comets to get the job done. This might sound like a pretty tall order, but it’s tiny compared to number of comets we’d need for your Mars or Venus real estate scheme.

The maintenance and upkeep isn’t going to be without its challenges. Low gravity on the Moon means that it can’t hold onto its atmosphere for longer than a few thousand years.

Once you got the process going, you’d need to be constantly replenishing our your orbital cottage with fresh atmosphere. Fortunately, we’ve got a whole Solar System’s worth of ice to exploit.

The benefits of a terraformed summer home on the Moon are numerous. For example, if the Moon had an atmosphere as thick as the Earth’s, you could strap on a pair of wings and fly around in the 1/6th gravity.

The enormous gravity of the Earth would pull the Moon’s oceans around the planet with 20 meter tides. You could surf the tide for kilometers as it washes across the surface in a miniature version of the shallow water scene in Interstellar.

This might be the greatest sponsorship opportunity for GoPro of all time. Look out Kiteboarding, you’re about to get more extreme.

Everyone always wants to talk about terraforming Venus or Mars. Let them be, that’s too much work. The next time someone brings it up at D&D night, you can blow their minds with your well crafted argument on why we want to start with the Moon.

I can remember David A. Hardy illustrating a few articles on future human habitats on the Moon, showing people enjoying themselves flying around and swimming at just such a lunar resort. One of these was for an article in the sadly short-lived space and astronomy magazine, New Voyager. The resort was in an enclosed dome, rather than on the terraformed surface. The Scots space scientist, Duncan Lunan, in his book, Man and the Planets, also suggested that to prevent the Moon’s atmosphere from being lost to space, the whole planet should be contained with a kind of giant inflatable bubble. This is waaaay beyond modern technological capability, but not, perhaps, that of the future. So perhaps at some point in the far future, the Moon may also join Earth as a living, habitable world.


David A. Hardy on Terraforming the Solar System

December 31, 2016

As well as colonising the other planets in the solar system with self-contained, sealed environments to protect their future human inhabitants, it may also one day be possible to terraform them. This means transforming them from their currently hostile conditions to an Earthlike environment. At the moment, the planet considered most suitable for terraforming is Mars, because of all the planets it seems to present the least obstacles to this form of planetary engineering. I can remember reading a piece in the Sunday Express way back in the 1980s, which discussed James Lovelock’s suggestions for creating an earthlike atmosphere on the Red Planet. Lovelock is the creator of the Gaia hypothesis, the theory that Earth’s biosphere acts like a gigantic, self-regulating organism. This became a favourite of several of the New Age neo-pagan religions in the 1990s, where it was incorporated into worship of the Earth Mother. Lovelock believed that while nuclear weapons were a serious danger to all life on Earth, they could be used creatively on Mars to produce an environment that would support life. Mars has large amounts of carbon dioxide locked up at its polar regions in the form of dry ice. he believed that this could be melted using nuclear missiles. Specially targeted nuclear explosions would cover the polar regions with an insulating layer of soil. This would keep the heat in, which is currently radiated back into space, reflected by the white ice. The rise in temperature would cause the dry ice to sublimate into carbon dioxide gas. This would then start a greenhouse effect, which would see more carbon dioxide and other gases released into the Martian atmosphere. This would eventually create an environment, where the atmosphere was thick enough for humans to be able to move around without space suits. They would, however, still need oxygen masks and tanks to be able to breathe. Lovelock was extremely optimistic about how many weapons would be needed. He believed that you’d only need four, if I remember correctly.

Lovelock’s ideas are wrong, but other scientists and Science Fiction writers have also suggested ways of transforming the Red Planet into a place where life can thrive. Back in the 1990s, Kim Stanley Robinson wrote a trilogy of books set on a Mars that was being colonised and terraformed by humanity, beginning with Red Mars. The veteran SF writer, Arthur C. Clarke, also produced a book in which he used to a computer programme to show what Mars may look like as it’s being terraformed. Over hundreds, perhaps even a thousand years, rivers, seas and oceans develop and green spreads over its land surface as vegetation begins growing on its previously barren surface.

David A. Hardy, the space artist, who has illustrated a number of books on space, including several with the late Patrick Moore, also described the various ways in which the Moon, as well as Mercury, Venus and Mars, could be terraformed in his 1981 book, Atlas of the Solar System (Kingswood, Surrey: World’s Work). He writes

Taking the concept of manned bases on other planets still further, there is the staggering possibility of ‘planetary engineering’ or terraforming – a term coined in 1942 by science fiction writer Jack Williamson. The idea is simply to make other worlds habitable by humans. An early suggestion, in 1961, by Carl Sagan was to ‘seed’ the atmosphere of Venus with blue-green algae, converting the carbon dioxide into oxygen and at the same time reducing the pressure and temperature (by eliminating the greenhouse effect). The upper clouds would condense and rain would fall, forming oceans.

A more recent alternative, now that we know how hostile Venus really is, is to ferry in ice asteroids 15 km or so in diameter, put them into orbit around Venus and aim them, using rocket jets, at a specific spot on the surface. Each crashes at nearly 100 km/s, at such an angle that Venus’ rotation is increased until a 24-hour day is approached, while at the same time water is provided as the ice melts. Then the atmosphere is seeded with blue-green algae.

The same could even be done with the Moon: once given a breathable atmosphere by baking oxygen out of the rocks with giant parabolic mirrors, it would remain for thousands of years, even if not replenished. The time factor for the operation is remarkably short. Mercury would need to be shielded from the Sun by a ‘parasol’ of rocky particles put up by mass-driver, or by a man-made ring. Mars would need to be warmed up, perhaps by reflecting sunlight on to the poles with huge, thin metal-foil mirrors, increasing the energy-flow at the poles by 20 per cent. or we could spread dark material from its carbonaceous moons on them with a mass-driver. Rich not only in carbon but in oxygen, nitrogen and hydrogen, this is excellent raw material for fertiliser. One the atmosphere was thickened, the greenhouse effect and carefully chosen plant life should do the rest. (pp. 86-7).

The process of transforming these planets into habitable worlds would take quite a long time – decades, if not centuries, and at present it is the stuff of science fiction. But I hope that there will be a time when we can move out from Earth to create new homes for life and civilisation on these worlds.

Space Scientist John S. Lewis on Prosperity and the Colonisation of the Asteroid Belt

December 27, 2016

I found this really interesting, optimistic passage below in John S. Lewis’ Mining the Sky (Reading, Massachusetts: Addison-Wesley 1997).

John S. Lewis is the Professor of Planetary Sciences and Codirector of the Space Engineering Research Center at the University of Arizona-Tucson. Subtitled, Untold Riches from the Asteroids, Comets and Planets, the book discusses the ways the immense mineral wealth of the solar system and the access it gives to the energy available from the Sun through solar power can be exploited through the colonisation of the solar system with present-day space technology, or developments from it that can reasonably be expected. The chapter ‘The Asteroid Belt: Treasure Beyond Measure’ describes the vast resources of the tiny, rocky worldlets of that part of the solar system, situated between the orbits of Mars and Jupiter. Not only does he describe the various metals and other minerals available there, but he also discusses the vast increase in personal wealth that would be given to nearly everyone on Earth if the money gained from the mining of these minerals were shared out equally.

I do not want to leave the impression that enough mineral wealth exists in the asteroid belt to provide $7 billion for each person on Earth. That would not be fair. In fact, this estimate completely ignores the value of all th other ingredients of asteroids besides iron. We know, for example, that for every ton of iron in the asteroids, there’s 140 pounds of nickel. That comes to about $6 billion worth of nickel. Meteorite metals contain about 0.5 percent cobalt, which sells for about $15 a pound. That gives another $26 billion each. The platinum-group metals, which sell for about $460 per troy ounce ($15 per gram, or $6,800 per ound) make up about fifteen parts per million of meteorite metal. That comes to another $1.6 X 10 X 20, which is $32 billion per person. So far that is about $72 billion each, and we are not close to done. Add in gold, silver, copper, manganese, titanium, the rare earths, uranium, and so on, and the total rises to over $100 billion for each person on Earth.

It appears that sharing the belt’s wealth among five billion people leads to a shameless level of affluence. Each citizen, assuming he or she could be persuaded to work a forty-hour week, could spend every working hour for 70 years counting $100 bills at the rate of one per second (that’s $360,000 per hour) and fail to finish counting this share of the take. If we were instead to be satisfied with an average per capita wealth comparable to that in the upper economic classes of the industrialised nations today, roughly $100,000 per person, then the resources of the belt would suffice to sustain a million times as many people on Earth. These 10 to the power of 16 people could all live as well as ninety-fifth percentile American of the late twentieth century. With recycling and an adequate source of power, this immense population is sustainable into the indefinite future. The best use of the wealth of the asteroid belt is not to generate insane levels of personal wealth for the charter members; the best use is to expand our supply of the most precious resource of all-human beings. People embody intelligence, by for the most precious resource in the universe and one in terribly short supply. (p. 196).

Now clearly, this is the ideal situation, presented without the risks and costs of actually reaching the asteroid belt and extracting the wealth bound up in its rocks. I also believe that in practice, much of that wealth would also be consumed by the mining companies or terrestrial government agencies responsible for the belt’s commercial exploitation. But it is refreshing to see humans viewed not as a cost in the process of production, which needs to be eliminated as much as possible, but as a valuable and indispensable resource, which needs to be used in the process of exploration and commercial exploitation as much as possible, and handsomely rewarded for its contribution.

On the next page, Lewis also describes the advantages of solar power for the future miners and colonists over fossil fuels and nuclear fission.

But wait a minute! Why not use solar power? The Sun pumps out power at the prodigious rate of 4 X 10 to the power of 33 ergs per second, equivalent to 4 X 10 to the power of 26 watts. Our supercivilisation needs 10 to the power of 19 watts to keep going. The Sun is pumping out forty million times as much power as we need! But what do we need to do to capture and use that energy? The simplest answer (not necessarily the best-there may be even more desirable options that we have not thought of yet) is to use vast arrays of solar cells to convert sunlight into electrical power. If the cells have an efficiency of about 20 percent, similar to the best commercial cells made at present, then each square meter of cell area exposed to the Sun near Earth’s orbit would generate 270 watts of electrical power continuously. We would need thirty-seven billion square kilometers of solar cells to provide our power needs, an area comparable to the total surface area of our habitats. At about 0.1 grams per square centimeter for the solar cells, we would need about 3.7 X 10 to the power of 19 grams of silicon to make the cells and perhaps three times as much metal to provide the supports and wires for the power-collection system. The asteroids give us 4X10 to the power of 23 grams of silicon, more than ten thousand times the amount we need for this purpose. The cost of the solar power units is set by the need to construct a few square meters of solar cells per person. The cost would be about two hundred dollars per person at present prices, or a few dollars per person at future mass-production prices. That is not your monthly electric bill: it is a one-time-only expenditure to provide all the electric power you will need for the rest of your life.

All this reckons with 1997 technology. New types of high-efficiency solar cells made of gallium arsenide or other exotic materials, combined with ultra-lightweight parabolic reflectors to collect and concentrate sunlight onto small areas of these cells, promise to perform much better than these highly conservative estimates. (pp. 197-8).

This is the solar power available for the asteroid colonies near Earth. In a later chapter, 14, Lewis discusses ‘Environmental Solutions for Earth’.

Lewis certainly isn’t against private industry in space. Indeed, in an imaginary scenario in one of the first chapters he has a future businessman enthusing about the profits to be gained from mining the Moon or other parts of the Solar system. But he’s clearly like many space visionaries in that he believes that humanity’s expansion into the cosmos will bring immense benefits in enriching and raising the personal quality of life for each individual as well as benefiting the environment down here on Earth.

But reading that paragraph on the benefits of solar power does show why some politicians, particularly in the Tory and Republican parties in Britain and America, who are the paid servants of the nuclear and fossil fuel companies, are so dead set against solar power, as well as other renewables. Quite simply, if it’s adopted, these industries immediately become obsolete, the obscene wealth enjoyed by their CEOs, senior management, and the aristocracy of Middle Eastern oil states, like Saudi Arabia, vanishes along with their political power. And the proles have access to cheaper power. Indeed, people using solar power today are actually able to reverse the usual norm slightly and sell power back to the grid.

No wonder the Tories are trying to shut it all down in favour of nuclear and fracking.

18th Century Religious Scepticism Not Based on Science: Part 3 – David Hume and Scepticism

June 9, 2013

David Hume’s Dialogues Concerning Natural Religion is one of the classic anti-religious texts. Hume was an agnostic sceptic, rather than an atheist materialist. Published after his death in 1779, the Dialogues are a sustained attack on Natural Theology. In them, Hume attacked the idea of the universe as a machine, and suggested other, organic metaphors. The universe could have grown instead like some kind of vegetable. He also criticised the idea that the features and characteristics of animals were proof of the existence of a Designer. He argued instead that an animal with a particular set of characteristics would have to follow a particular lifestyle or die out. This did not, however, show that those features were designed, or that the animal was intended to pursue this particular manner of existence. He also argued that the immense suffering in nature also argued against the existence of a benevolent deity. He also argued that the regular operation of natural laws also did not show that they were grounded in God’s will. He also argued that miracles were so highly improbably that they should not be accepted, and that if they did exist, they were not necessarily proof of God’s existence as every religion had them. As for the origin of religion itself, in his unpublished book, the Natural History of Religion, he believed that the original religion of humanity had been polytheism, the belief in many gods. This was in stark contrast to the Deists and orthodox Christians, who believed that the first religion had been monotheism. He also saw all religions as leading to fanaticism, and attacked religious virtues as being useless to society.

Hume’s Arguments not Accepted at Time, Criticism by Joseph Priestly

Hume’s Dialogues are considered by the majority of scholars as totally destroying the arguments for the Almighty’s existence based on nature. This is, however, very much a post-Darwinian view. Matt Ridley, in his collection of texts on evolution, places an extract from the dialogues in a section entitled ‘Philosophical Consequence of Evolution’. At the time it was felt that Joseph Priestley had decisively refuted Hume’s arguments in his 1780, Letters to a Philosophical Unbeliever. Priestley stated that

‘With respect to Mr. Hume’s metaphysical writings in general, my opinion is, that, on the whole, the world is very little the wider for them. For though, when the merits of any question were on his side, few men ever wrote with more perspicuity, the arrangement of his thoughts being natural, and his illustrations pecularliarly happy; yet I can hardly think that we are indebted to him for the least real advance in the knowledge of the human mind.’

Regarding Hume’s ideas on how humans form concepts, Priestley believed that they had all been refuted by Hartley’s Observations on Man, which Hume didn’t appear to have read.

‘He seems not to have given himself the trouble so much as to read Dr. Hartley’s Observations on Man, a work which he could not but have heard of, and which it certainly behoved him to study. The doctrine of association of ideas, as explained and extended by Dr. Hartley, supplies materials for th emost satisfactory solution of aolmost all the difficulties he has started, as I could easily show if I thought it any consequence; so that to a person acquainted with this theory of the human mind, Hume’s Essays appear the merest trifling. Compared iwth Dr. Hartley, I consider Mr. Hume as not even a child.’

Priestley was also highly critical of the quality of the arguments for the non-existence of God advanced by the character of Philo in the Dialogues. According to Priestly, the character of Philo advanced ‘nothing but common-place objections against the belief of a God, and hackneyed declamations against the plan of providence’.

Priestly was also unimpressed by Hume’s argument that analogies from animals and plants could also equally be used to explain the cosmos. Hume had suggested that if the universe were an animal, then comets could be viewed as this creature’s eggs. Priestley said of this

‘Had any friend of religion advanced an idea so completely absurd as this, what would not Mr. Hume have said to turn it into ridicule. With just a smuch probability might he have said that Glasgow grew from a seed yielded by Edinburgh, or that London and Edinburgh, marrying, by natural generation, produced York, which lies between them. With much more probability might he have said that pamphlets are the productions of large books, that boats are young ships, and the pistols will grow into great guns; and that either there never were any first towns, books, ships, or guns, or that, if there were, they no makers.

How it could come into any man’s head to imagine that a thing so complex as this world, consisting of land and water, earths and metals, plants and animals, &c &c &c should produce a seed, or egg, containing within it the elements of all its innumerable parts, is beyond my powers of comprehension.’

Hume’s Argument on Organic Nature of Universe Scientific Nonsense, According to Priestly

Priestly even suggested that this view of the origin of the cosmos was based on ignorance, not science.

‘What must have been that man’s knowledge of philosophy and nature, who could suppose for a moment, that a comet could possibly be the seed of a world? Do comets spiring from worlds, carrying with them the seeds of all the plants, &c that they contain? Do comets travel from sun to sun, or from star to star? By what force are they tossed into the unformed elements, which Mr. Hume supposes everywhere to surround the universe?> What are those elements: and what evidence has he of their existence? or supposing the comet to arrive among them, whence could arise its power of vegetating into a new system?’

Priestly had possibly missed the point about HUme’s organic analogies. They were not serious suggestions, but intended to show that the machine metaphors used for the universe were only one of several that could equally be used. Nevertheless, Priestly showed that these metaphors were just as, if not more vulnerable, to criticism as those which likened the cosmos to a machine.

Hume’s Spokesman for Design Champion of Science in these Debates

Most of Hume’s arguments against religion and the evidence for design in the universe are philosophical, not scientific. He does use Newton’s suggestion that the cosmos was permeated by an ether to argue that it was movements in this, rather than the actions of the Almighty, that resulted in the effects of gravity. Despite this it is Hume’s character, Cleanthes, who idealises and defends science. Cleanthes states that ‘The true system of the heavenly bodies is discovered and ascertained … Why must conclusions of a (relgious) nature be alone rejected on the general presumption of the insufficiency of human reason?’

Hume’s Empiricism also Used to Attack Not Yet Verified Scientific Concepts

Furthermore, Hume’s agnosticism could act against scientific investigation. Hume believed that just because two events were seen to occur together did not mean that one caused the other. Hume did not wish to attack science. He was an empiricist, and this attitude that no concepts should be accepted unless they were directly experienced could be used against scientific ideas as well as religious, if taken to extremes. Atoms and genes, for example, were theoretical suggestions long before they were verified by science. These concepts would have had to be rejected if the standards of evidence Hume levelled against religion were applied to science. Those secular scientists that did not believe in them frequently attacked them on the basis that such ideas were exactly like those of religion in their lack of a sound scientific basis. The great 19th century chemist, Marcellin Berthelot, stated:

‘I do not want chemistry to degenerate into a religion; I do not want the chemist to believe in the existence of atoms as the Christian believes in the existence of Christ in the communion wafter’.

Refutation of the Argument against Miracles and Other Arguments

As for Hume’s arguments against miracles, they have been refuted by the secular, agnostic philosopher Earman. Earman’s article attacking them was called ‘The complete Failure of Hume’s Arguments against Miracles’. Hume’s arguments against design in the cosmos have also been attacked by Robin Attfield in his Creation, Evolution and Meaning (Aldershot: Ashgate 2006). Attfield argues against atheism from a theistic evolutionist perspective.

As for Hume’s argument that monotheism originally arose from polytheism, this has been accepted by theologians as not actually affecting the truth of the Christian revelation. I was taught it at my old Anglican church school. There is another theory that the original religion was monotheism. This is based on similarities to Judeo-Christian conception of the Almighty in other cultures, and by the fact that rather than developing into monotheism, the number of gods in polytheist religions actually increases over time.

Conclusion: Hume’s Arguments Philosophical, Not Scientific, and Could be Used Against Science

Thus Hume’s arguments against religion have been attacked in turn, and were largely not based in science. Joseph Priestly, who was a scientist as well as Unitarian minister, attacked them for their lack of a scientific basis. Indeed, Hume’s empiricism, when taken to extremes, could and did occasionally act against scientific discovery, as Berthelot’s rejection of atoms shows.


John Hedley Brooke, Science and Religion: Some Historical Perspectives (Cambridge: Cambridge University Press 1991).