The Apollo Program – More Memories from Fifty Years Ago.

As most will know, it is fifty years ago since the first Moon landing. I was doing a post-doc in Australia at the time, and instead of doing any work that morning, when the word got around on that fateful day we all downed tools and headed to anyone with a TV set. The Parkes radio telescope had allowed what they received to be live-streamed to Australian TV stations. This was genuine reality TV. Leaving aside the set picture resolution, we were seeing what Houston was seeing, at exactly the same time. There was the Moon, in brilliant grey, and we could watch the terrain get better defined as the lander approached, then at some point it seemed as if the on-board computer crashed. (As computers go, it was primitive. A few years later I purchased a handheld calculator that would leave that computer for dead in processing power.) Anyway, Armstrong took control, and there was real tension amongst the viewers in that room because we all knew if anything else went wrong, those guys would be dead. There was no possible rescue. The ground got closer, Armstrong could not fix on a landing site, the fuel supply was getting lower, then, with little choice because of the fuel, the ground got closer faster, the velocity dropped, and to everyone’s relief the Eagle landed and stayed upright. Armstrong was clearly an excellent pilot with excellent nerves. Fortunately, the lander’s legs did not drop into a hole, and as far as we could tell, Armstrong chose a good site. Light relief somewhat later in the day to watch them bounce around on the lunar surface. (I think they were ordered to take a 4-hour rest. Why they hadn’t rested before trying to land I don’t know. I don’t know about you, but if I had just successfully landed on the Moon, and would be there for not very long, a four-hour rest would not seem desirable.)

In some ways that was one of America’s finest moments. The average person probably has no idea how much difficult engineering went into that, and how everything had to go right. This was followed up by six further successful landings, and the ill-fated Apollo 13, which nevertheless was a triumph in a different way in that despite a near-catastrophic situation, the astronauts returned to Earth.

According to the NASA website, the objectives of the Apollo program were:

  • Establishing the technology to meet other national interests in space.
  • Achieving preeminence in space for the United States.
  • Carrying out a program of scientific exploration of the Moon.
  • Developing human capability to work in the lunar environment.

The first two appear to have been met, but obviously there is an element of opinion there. It is debatable that the last one achieved much because there has been no effort to return to the Moon or to use it in any way, although that may well change now. Charles Duke turns 84 this year and he still claims the title of “youngest person to walk on the Moon”.

So how successful was the scientific program? In some ways, remarkably, yet in others there is a surprising reluctance to notice the significance of what was found. The astronauts brought back a large amount of lunar rocks, but there were some difficulties here in that until Apollo 17, the samples were collected by astronauts with no particular geological training. Apollo 17 changed that, but it was still one site, albeit with a remarkably varied geological variety. Of course, they did their best and selected for variety, but we do not know what was overlooked.

Perhaps the most fundamental discovery was that the isotopes from lunar rocks are essentially equivalent to earth rocks, and that means they came from the same place. To put this in context, the ratio of isotopes of oxygen, 16O/17O/18O varies in bodies seemingly according to distance from the star, although this cannot easily be represented as a function. The usual interpretation is that the Moon was formed when a small planet, maybe up to the size of Mars, called Theia crashed into Earth and sent a deluge of matter into space at a temperature well over ten thousand degrees Centigrade, and some of this eventually aggregated into the Moon. Mathematical modelling has some success at showing how this happened, but I for one am far from convinced. One of the big advantages of this scenario is that it shows why the Moon has no significant water, no atmosphere, and never had any, apart from some water and other volatiles frozen in deep craters at the South Pole that almost certainly arrived from comets and condensed there thanks to the cold. As an aside, you will often read that the lunar gravity is too weak to hold air. That is not exactly true; it cannot hold it indefinitely, but if it started with carbon dioxide proportional in mass, or even better in cross-sectional area, to what Earth has, it would still have an atmosphere.

One of the biggest disadvantages of this scenario is where did Theia come from? The models show that if the collision, which happened about 60 million years after the Earth formed, occurred from Theia having a velocity much above the escape velocity from Earth, the Moon cannot form. It gets the escape velocity from falling down the Earth’s gravitational field, but if it started far enough further out that would have permitted Theia to have lasted 60 million years, then its velocity would be increased by falling down the solar gravitational field, and that would be enhanced by the eccentricity of its trajectory (needed to collide). Then there is the question of why are the isotopes the same as on Earth when the models show that most of the Moon came from Theia. There has been one neat alternative: Theia accreted at the Earth-Sun fourth or fifth Lagrange point, which gives it indefinite stability as long as it is small. That Theia might have grown just too big to stay there explains why it took so long and starting at the same radial distance as Earth explains why the isotope ratios are the same.

So why did the missions stop? In part, the cost, but that is not a primary reason because most of the costs were already paid: the rockets had already been manufactured, the infrastructure was there and the astronauts had been trained. In my opinion, it was two-fold. First, the public no longer cared, and second, as far as science was concerned, all the easy stuff had been done. They had brought back rocks, and they had done some other experiments. There was nothing further to do that was original. This program had been a politically inspired race, the race was run, let’s find something more exciting. That eventually led to the shuttle program, which was supposed to be cheap but ended up being hideously expensive. There were also the deep space probes, and they were remarkably successful.

So overall? In my opinion, the Apollo program was an incredible technological program, bearing in mind from where it started. It established the US as firmly the leading scientific and engineering centre on Earth, at least at the time. Also, it got where it did because of a huge budget dedicated to one task. As for the science, more on that later.

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Earth’s Twin: Venus

Leaving aside the Moon and the Sun, Venus is the brightest object in the sky, and at times the closest. Further, Venus is the only planet that is comparable to Earth; its mass is about 81.5%, its size is about 95%, and its gravity is about 90.5% that of Earth. The orbit of Venus has only 1/3 of Earth’s eccentricity, and while Earth has an axial tilt of 23.5 degrees (which results in right now I am embedded in winter and many of the readers will be enjoying a pleasant summer, or maybe a heat wave) Venus has a tilt of only 2.6 degrees. That means that Venus has a more or less uniform temperature and no seasons. At first sight, that would make it an attractive target for space probes, but while NASA has sent eleven orbiters and eight landers to Mars, it has only sent two orbiters to Venus. Why the lack? Not for lack of interest since from 1990 NASA has considered nearly thirty proposals, but it approved none. The dead hand of the committee strikes again. The reason is that Venus, up close, is strangely unattractive.

The first problem is atmospheric pressure, which is about 90 bar over most of the planet, and it has an average surface temperature of about 460 degrees C but this can vary by +160 degrees C. The second problem is the nature of the atmosphere. Most of it is carbon dioxide. Venus also has about four times the amount of nitrogen than Earth has, and all of that is relatively harmless. What is less harmless is the atmosphere has clouds of sulphuric acid, together with hydrogen chloride and hydrogen fluoride. Hydrogen fluoride is particularly nasty, because it reacts with glass, and while the sulphuric acid will attack all the basic electronics, etc, the hydrogen fluoride will attack lenses. Very shortly, photography, or seeing where a rover is going, will no longer be possible. And, of course, if it can survive, the heat soon kills it. The first lander to return data was Venera 7, a 1970 Soviet lander that survived for 23 minutes. In 1975, Venera 9 sent back the first pictures from the surface, but it too did not last very long. Funding committees do not encourage very expensive rovers with a very short life.

This may change. NASA is designing a “station” that should last at least sixty days, and operate at the ambient temperature. The electronics would be made of silicon carbide, a substance that conducts electricity and melts somewhere above 2,800 degrees C. No danger of that melting, although all the metals in the craft would have to be resistant to the ambient heat and the corrosion. Titanium would probably manage reasonably well. So maybe we shall get to know more about the planet.

There have apparently been proposals to “colonise” Venus through “settlements” floating above the cloud levels, i.e.presumably some ship-like structure supported by gigantic balloons. Personally, I feel this is unreal. The total weight must displace an equal weight of gas, and the idea is to get above the clouds. Up there, the gas is nowhere near as dense (the pressure is only about half that 90 bar at the top of the highest mountain) and to go higher the pressure really drops away. So to support sufficient mass you would need very large balloons, made of what? Any fabric or rubber would be broken down by the solar UV at that height. Metals would corrode. And what would the gas be? The obvious ones would be hydrogen and helium (no danger of fire because there is no air) but these gases leak like crazy. You may think you can hold it, but for centuries? Then there is another minor problem: at the top of the atmosphere winds can reach several hundred kilometres per hour.

So what is “wrong” with Venus, from our point of view? There are two things. The first is the very slow rotation, which happens to be retrograde. The direction is not so much a problem, but the slowness is. However, the main one is, no significant water. If Venus had the amount of water Earth has, it would have fixed all that carbon dioxide as limestone or dolomite, in which case the atmospheric pressure would be about 3 times our atmosphere (because it has four times the amount of nitrogen). If we wanted to have breathable air, we would have to add another atmosphere of oxygen.

So in theory we could terraform Venus. At the expense of much energy what we would have to do is bring in a number of Kuiper Belt objects, or maybe cometary material from around Jupiter would be better because they contain much less additional nitrogen and carbon monoxide, and make them hit Venus, preferably on the side in a way that the angular momentum of the incoming object was added to the current Venusian rotation, in other words, spin it up. Give it water, and chemistry would do the rest, although it would probably also be preferable to cool it by shading it from the sun at least to some extent. Yes, the temperatures would still be high, but as long as it can cool to 300 degrees C, the pressure will ensure there is some liquid, and the fixing of the gas will start, and initiate positive feedback

Suppose we could give Venus as much water as Earth, then the planet would be more like a water world. It is an interesting question whether Venus has any felsic/granitic material. This is the stuff that makes continents. The great bulk of the material on any rocky planet is basaltic, which in turn is because the oxides of silicon, magnesium and iron are the most commonly available rock-forming materials. Aluminium, as an element, is over an order of magnitude less common than silicon, which it replaces in aluminosilicates. Being less dense than basalt, granite floats on the basalt, provided it can separate itself from the basalt. In my ebook “Planetary Formation and Biogenesis”, I propose that the separation essentially has to take place prior to and during planetary formation. Venus does have two minicontinents: Ishtar and Aphrodite Terrae.

The actual differentiation of the planet, when the granite moves from the deep and comes out on the surface occurs slowly (the small amounts of plagioclase on Mars apparently took about two billion years.) and the rate probably depends on the amount actually accreted. The evidence is that on Earth very large amounts erupted in massive pulses. In the absence of such granite, a large planet will be rather flat, apart from some volcanic peaks.

There would still be a problem in that Venus has no plate tectonics. They are needed to provide the recycling of carbon dioxide, as eventually if the lot were fixed, any life would presumably die. We don’t know what starts plate tectonics. One possibility is the presence of granitic continents, another is the forces arising from rotational motion.  It is just possible they could start if there were more rotational motion, but we don’t know. All in all, not an attractive planet in detail, so maybe we should look after our own better.

The Ice Giants’ Magnetism

One interesting measurement made from NASA’S sole flyby of Uranus and Neptune is that they have complicated magnetic fields, and seemingly not the simple dipolar field as found on Earth. The puzzle then is, what causes this? One possible answer is ice.

You will probably consider ice as not particularly magnetic nor particularly good at conducting electric current, and you would be right with the ice you usually see. However, there is more than one form of ice. As far back as 1912, the American physicist Percy Bridgman discovered five solid phases of water, which were obtained by applying pressure to the ice. One of the unusual properties of ice is that as you add pressure, the ice melts because the triple point (the temperature where solid, liquid and gas are in equilibrium) is at a lower temperature than the melting point of ice at room pressure (which is 0.1 MPa. A pascal is a rather small unit of pressure; the M mean million, G would mean billion). So add pressure and it melts, which is why ice skates work. Ices II, III and V need 200 to 600 MPa of pressure to form. Interestingly, as you increase the pressure, Ice III forms at about 200 Mpa, and at about -22 degrees C, but then the melting point rises with extra pressure, and at 350 MPa, it switches to Ice V, which melts at – 18 degrees C, and if the pressure is increased to 632.4 MPa, the melting point is 0.16 degrees C. At 2,100 MPa, ice VI melts at just under 82 degrees C. Skates don’t work on these higher ices. As an aside, Ice II does not exist in the presence of liquid, and I have no idea what happened to Ice IV, but my guess is it was a mistake.

As you increase the pressure on ice VI the melting point increases, and sooner or later you expect perhaps another phase, or even more. Well, there are more, so let me jump to the latest: ice XVIII. The Lawrence Livermore National Laboratory has produced this by compressing water to 100 to 400 GPa (1 to 4 million times atmospheric pressure) at temperatures of 2,000 to 3,000 degrees K (0 degrees centigrade is about 273 degrees K, and the scale is the same) to produce what they call superionic ice. What happens is the protons from the hydroxyl groups of water become free and they can diffuse through the empty sites of the oxygen lattice, with the result that the ice starts to conduct electricity almost as well as a metal, but instead of moving electrons around, as happens in metals, it is assumed that it is the protons that move.

These temperatures and pressures were reached by placing a very thin layer of water between two diamond disks, following which six very high power lasers generated a sequence of shock waves that heated and pressurised the water. They deduced what they got by firing 16 additional high powered lasers that delivered 8 kJ of energy in a  one-nanosecond burst on a tiny spot on a small piece of iron foil two centimeters away from the water a few billionths of a second after the shock waves. This generated Xrays, and from the way they diffracted off the water sample they could work out what they generated. This in itself is difficult enough because they would also get a pattern from the diamond, which they would have to subtract.

The important point is that this ice conducts electricity, and is a possible source of the magnetic fields of Uranus and Neptune, which are rather odd. For Earth, Jupiter and Saturn, the magnetic poles are reasonably close to the rotational poles, and we think the magnetism arises from electrically conducting liquids rotating with the planet’s rotation. But Uranus and Neptune have quite odd magnetic fields. The field for Uranus is aligned at 60 degrees to the rotational axis, while that for Neptune is aligned at 46 degrees to the rotational axis. But even odder, the axes of the magnetic fields of each do not go through the centre of the planet, and are displaced quite significantly from it.

The structure of these planets is believed to be, from outside inwards, first an atmosphere of hydrogen and helium, then a mantle of water, ammonia and methane ices, then interior to that a core of rock. My personal view is that there will also be carbon monoxide and nitrogen ices in the mantle, at least of Neptune. The usual explanation for the magnetism has been that magnetic fields are generated by local events in the icy mantles, and you see comments that the fields may be due to high concentrations of ammonia, which readily forms charged species. Such charges would produce magnetic fields due to the rapid rotation of the planets. This new ice is an additional possibility, and it is not beyond the realms of possibility that it might contribute to the other giants.

Jupiter is found from our spectroscopic analyses to be rather deficient in oxygen, and this is explained as being due to the water condensing out as ice. The fact that these ices form at such high temperatures is a good reason to believe there may be such layers of ice. This superionic ice is stable as a solid at 3000 degrees K, and that upper figure simply represents the highest temperature the equipment could stand. (Since water reacts with carbon, I am surprised it got that high.) So if there were a layer of such ice around Jupiter’s core, it too might contribute to the magnetism. Whatever else Jupiter lacks down there, pressure is not one of them.

Asteroid (101955) Bennu

The results of the OSIRIS-REx probe have now started to be made public, and while this probe was launched to answer questions about carbonaceous asteroids, and while some information has been obtained that is most certainly interesting, what it has mainly done, in my opinion, is to raise more questions. As is often the case with scientific experiments and observations.

Bennu is a carbonaceous asteroid with a semimajor axis of about 1.26 AU, where 1 AU is the Earth-Sun distance. Its eccentricity is 0.2, which means it is Earth-crossing and could collide with Earth. According to Wikipedia, it has a 1 in 2700 chance of impacting Earth between 2175 – 2199. I guess I shall never know, but it would be a threat. It has a diameter of approximately 500 meters, and a mass of somewhere in the vicinity of 7 x 10^10 kg, which means an impact would be extremely damaging near where it struck, but it would not be an extinction event. (The Chicxulub impactor would have been between five to seven orders of magnitude bigger.) So, what do we know about it?

It is described as a rubble pile, although what that means varies in terms of who says it. It is generally not considered to be an original accretion, and it is usually assumed to have formed inside a much larger planetoid which provided heat and pressure to form more complex minerals. Exactly why they are so sure of this is a puzzle to me, because we do not know what the minerals are, and how they are bound into the asteroid. Carbonaceous asteroids usually are found in the outer asteroid belt, and the assumption is this was dislodged inwards as a result of the collision that formed it. Standard theory assumes there were such collisions, but it also assumes such collisions led to planetary formation, and the rather awkward fact that there are no planets in the asteroid belt tends to be overlooked. These collisions are doing a lot of work, first making protoplanets then planets, and second, smashing up protoplanets to make asteroids, with no explanation why two different results arise other than “we need two different results”. Note that the collision velocities in the asteroid belt would be much milder than for the rocky planets, so smashing is more likely the closer to the star. Its relevance to planetary formation may be low since it did not form a planet, and there are no planets that have compositions that could realistically be considered to have come from such a chemical composition.

It is often said that Earth was bombarded with carbonaceous chondrites early on, and that is where the reduced carbon and nitrogen came from to sustain life, as well as the amino acids and nucleobases used to create life. Additionally, it is asserted that the iron and a number of other metals that dissolve in iron that we have on the surface must have come from asteroids, the reason being that in the early formation of Earth, the whole was a mass of boiling silicates in which such metals would dissolve in iron and go to the core. That we have them means something else must have brought them later. This shows one of the major faults of science, in my opinion. Rather than take the observation as a reason to go back and question whether the boiling silicates might be wrong, they introduce a further variable. Unfortunately, this “late veneer”  is misleading because the advocates have refused to accept that we have fragments of asteroids as meteorites. Their isotopes show they could only have contributed the right amount of metals, etc, if they were emulsified in all of Earth’s silicates. But wait. Why would these be emulsified and not go to the core while the original metals were not emulsified and did go to the core?

These asteroids are also believed by many to be the origin of life. They have very small amounts of amino acids and nucleobases, but they have a much wider range of amino acids than are used by our life. If they were the source, why did we not use them? Even more convincing, the nitrogen in the meteorite fragments has more 15N than Earth’s nitrogen. Ours is of solar composition; the asteroids apparently processed it. There is no way to reduce the level of heavy isotopes so these asteroids cannot be the source.

Now, what does a rubble pile conjure up in your mind? I originally considered it to be, well, a pile of rubble, loosely adhering, but Bennu cannot be that. First, consider the escape velocity, which is more than 20 cm/sec in the polar regions but reduces down to 10 cm/sec at the equator, due to the centrifugal force of its rotation. That is not much, and anything loose would be lost in any impact. Yet the surface is littered with boulders, three more than 40 m long. Any significant shock would seemingly dislodge such boulders, especially smaller ones, but there they are, some half buried. There are also impact craters, some up to 150 meters in diameter. Whatever hit it to create that and excavate a hole 150 m in diameter must have delivered a shock wave that should impart more than 10 cm s−1 to a loosely lying boulder, although there is one possible exception, which is when the whole structure was sufficiently flexible to give without fragmenting and absorb the energy by converting it to heat while adding to the kinetic energy of the whole.

Which brings us back to the rubble pile. Bennu’s relative density is 1.19, so if placed in water it would not float, but it would not sink very quickly either. For comparison, it is less than half that of granite and about a third of many basalts. CI asteroidal material has a bulk density of 1.57, while CM asteroidal material has a bulk density of 2.2.  Accordingly, it is concluded that Bennu has a lot of voids in it, which is where the concept of the rubble pile comes to bear. On the other hand, there is considerable stiffness, so something is restricting movement.

So what do we not know about this asteroid? First, we have only a modest idea of what it is made of, although a sample return might be possible. It may well be made entirely of large boulders plus the obvious voids put together with something sticking the boulders together, but what is the something? If made of boulders, what are the boulders made of? It never got hot enough out there to melt silicates, so whatever they are must b held together by some agent, but what? How resilient is that something, and how many times can it be used before it fails? This is important in case we decide it would be desirable to alter its orbit to avoid a collision with Earth. What holds the boulders together? This is important if we want to know how planets form, and whether such an asteroid will be useful in any way. (If, for example, we were to build a giant space station, the nitrogen, organic material and water in such an asteroid would be invaluable.) More to do to unravel this mystery.

Processing Minerals in Space

I have seen some recent items on the web that state that asteroids are full of minerals and fortunes await. My warning is, look deeper. The reason is, most asteroids have impact craters, and from basic physics but some rather difficult calculations you can show these were formed from very energetic collisions. That the asteroid did not fly to bits indicates it is a solid with considerable mechanical strength. That implies the original dust either melted to form a solid, or a significant chemical reaction took place. For those who have read my “Planetary Formation and Biogenesis” you will know why they melted, assuming I am right. So what has that got to do with things? Quite simply, leaving aside metals like gold, the metal oxides in molten silica form the olivine or pyroxene families, or aluminosilicates. That is they form rocks. To give an example of the issue, I recently read a paper where various chondrites were analysed, and the method of analysis recorded the elements separately. The authors were making much of the fact that the chondrites contained 19% iron. Yikes! But wait. Fayalite contains almost 55% iron by weight, but it is useless as an ore. The olivine and pyroxene structures have tetrahedral silicon oxides (the pyroxene as a strand polymer) where the other valence of the oxygen is bound to a divalent cation, mostly magnesium because magnesium is the most common divalent element in the supernova dust. What these authors had done was to analyse rock.

If you read my previous post you will see that I have uncovered yet another problem with science: the authors were very specialized but they went outside their sphere of competency, quite accidentally. They cited numbers because so much in science depends on numbers. But it is also imperative to know what the numbers mean.

On Earth, most of the metals we obtain come from ores, which have formed through various forms of geochemical processing. Thus to get iron, we usually process haematite, which is an iron oxide, but the iron almost certainly started as an average piece of basalt that got weathered. It is most unlikely that good deposits of haematite will be found on asteroids, although it is possible on Mars where small amounts have been found. If Mars is to be settled, processing rocks will be mandatory for survival but the problems are different from those of asteroids. For this post, I wish to restrict myself to discussing asteroids as a source of metals. Let us suppose an asteroid is collected and brought to a processing site, the question is, what next?

The first problem is size-reduction, i.e.breaking it down to more manageable pieces. How do you do that? If you hit it with something, you immediately separate, following Newton’s third law. If you want to see the difficulties, stand on a small raft and try to keep on hitting something. Ah, you say, anchor yourself. How? You have to put something like a piton into solid rock, and how do you do that without some sort of impact? Of course it can be done, but it is not easy. Now you start smashing it. What happens next is bits of asteroid fly off into space. Can you collect all of the pieces? If not, you are a menace because the asteroid’s velocity v, which will be in the vicinity of 30 km/s if near Earth, has to be added to whatever is given to the fragments. Worse, they take on the asteroid’s eccentricity ε(how much difference there is between closest and farthest distance from the sun) and whatever eccentricity has been added by the fragmentation. This is important because the relative velocity of impact assuming the target is on a circular orbit is proportional to εv. Getting hit by a rock at these sort of velocities is no joke.

However, suppose you collect all the rock, you have two choices: you can process the rock as is, or you can try to refine it. If you adopt the latter idea, how do you do it? On Earth, such processing arises through millions of years of action with fluids, or through superheated fluids passing through high temperature rock. That does not sound attractive. Now some asteroids are argued to have iron cores so the geochemical processing has been done for you. Of course you still have to work your way through the rock, and then you have to size reduce the iron, which again raises the question, how? There is also a little less good news awaiting you: iron cores are almost certainly not pure iron. The most likely composition is iron with iron silicide, iron phosphide, iron carbide and a lot of iron sulphide. There will also be some nickel, together with corresponding compounds, and (at last joy?) certain high value metals that dissolve in iron. So what do you do with this mess?

Then, supposing you separate out a pure chemical compound, how do you get the metal out? The energy input required can be very large. Currently, there is a lot of effort being put into removing CO2from the atmosphere. The reason we do not pull it apart and dump the carbon is that all the energy liberated from burning it has to be replaced, i.e.a little under 400 kJ/mol. and that is such a lot of energy. Consider that as a reference unit. It takes roughly two such units to get iron from iron oxide, although you do get two iron atoms. It takes about five units to break forsterite into two magnesium atoms and one silicon. It takes ten such units to break down kaolinite to get two aluminium atoms and two silicon atoms. Breaking down rock is very energy intensive.

People say, electrolysis. The problem with electrolysis is the material has to dissolve in some sort of solvent and then be separated into ions. Thus when making aluminium, bauxite, an aluminium oxide is used. Clays, which are aluminosilicates such as kaolinite or montmorillinite, are not used, despite being much cheaper and more easily obtained. In asteroids any aluminium will almost certainly be in far more complicated aluminosilicates. Then there is the problem of finding a solvent for electrolysis. For the least active metals, such as copper, water is fine, but that will not work for the more active ones, such as aluminium. Titanium would be even more difficult to make, as it is made from the reduction of titanium tetrachloride with magnesium. You have to make all the starting materials!

On Earth, many oxides are reduced to metal by heating with carbon (usually very pure coal) and allow the carbon to take the oxygen and disappear as a gas. The problem with that, in space, is there is no readily available source of suitable carbon. Carbonaceous chondrites have quite complicated molecules. The ancients used charcoal, and while this is NOT pure carbon, it is satisfactory because the only other element there in volume tends to be oxygen. (Most charcoal is about 35% oxygen.) The iron in meteors could certainly be useful, but for some other valuable elements, such as platinum, while it may be there as the element, it will probably be scattered through the matrix and be very dilute.

Undoubtedly there will be ways to isolate such elements, but such methods will probably be somewhat different from what we use. In some of my novels I have had fusion power tear the molecules to atoms, ionise them, and separate out the elements in a similar way to how a mass spectrometer works, that is they are accelerated and then bent with powerful electromagnetic fields. The “bend” in the subsequent trajectory depends on the mass of the ions, so each isotope is separated. Yes, that is fiction, but whatever is used would probably seem like fiction now. Care should be taken with any investment!

Space Law

One of the more notable recent events was the launching of a non-government rocket by a company run by Elon Musk to the International Space Station. Apparently Boeing is going to do something similar in the not too distant future. In some ways this is exciting, because one way or another, human ventures into space will increase markedly. I recall in 1969 sitting in front of a TV one morning (I was in Australia) getting direct feed from Parkes to see the first Moon landing in real time. (OK, there was a slight delay due to the speed of light, and probably more due to feed looping, but you know what I mean.) There was real tension because while everyone was reasonably confident that NASA had selected a good site, it was always possible the ground was not as solid as it might appear and it only needed for the lander to roll over and the ending might have been less than happy. Additionally, the landing was not entirely optimal, and fuel consumption was a little higher than anticipated. This may not seem important, but it did at the time. But all ended well. There were several more Moon landings, and apart from Apollo 13, the program was brilliantly successful. The recovered rocks are still yielding scientific information.

Then the program ended. And nothing more happened. We constructed the International Space Station, with reusable shuttles, but somehow this has had limited value. Certainly, it has permitted the testing of the effects of long periods of weightlessness on people and on other life forms. The best part of this was we got international cooperation. Arguably, humanity was going into space and not just various countries. We have sent a battery rovers and space craft through the solar system, and we genuinely know a lot more about our planetary system. When I was a schoolboy, I believe I knew as much about the planets, other than their orbital details, as anyone. That may sound ridiculous, but I believe it to be true because basically nobody knewvery much at all. They guessed on the basis of their observations, and their guesses were largely wrong. So that part of the space program has been a resounding success, but it brings into question, what is the point of acquiring that information if we do nothing with it? If we do, who does? If different parties go to space, what will be the rules they must follow? Who decides? It is much better if we can get this sorted before various parties get there.

There are two schools of thought. One is, we should stay here and leave the rest of the solar system for careful study, or if we do go somewhere, like Mars, again it should be for study, and we should leave it alone. The other school of thought is the solar system is a resource, and we should be free to tap into it. Which brings up the question, who decides? And what happens if someone does something another group decides should not be done? What happens if one government decides to do something, and a private company decides to do something similar in the same place? How are issues such as these to be resolved?

On Earth, we use the courts to resolve many such issues, although for some issues, governments decide, and of course the split between governments and courts varies from country to country. Worse than that, there is often no real logical reason to prefer one route over another, and the decision is made through politics. Again, different countries have different political systems, so two countries might reach very different decisions based properly on the way they conduct their affairs. Often enough, the various countries find that there is an impasse in finding common ground. What then? Carl von Clausewitz’ “war is a continuation of politics by other means” is not where we want to end up.

There is another problem. For a court to resolve something, there has to be law, and law follows from sovereignty, that is, the right to impose the law, AND the means of enforcing it. So, what happens in space? There is no sovereignty, and suppose there were settlers on Mars, why should they not have their own sovereignty? While they might start off as a colony, through needing a lot of support from people on Earth, their laws should not be imposed by people who have no concept of what life is like there. For example, environmental laws to conserve nature on Earth should not be imposed on Mars, where settlers would struggle just to get what they need to stay alive. Additionally, why would Russian settlers on Mars have to obey American laws, or vice versa? We might argue that the United Nations should set the laws for space, but unless all countries interested in exploring space agreed to them, why should they? Why should countries with no interest in space have standing in setting such laws?

Then there is the question of enforcement. The US is creating a “Space Force” so what happens if they try to stop Russians, say, from doing something in space that the US does not like? Settlements on planets are another matter. There, in my opinion, enforcement will have to fall on settlements, if for no other reason than if a crime is committed on Mars, we cannot have the situation where everyone has to wait for possibly a year and a half to get investigators from Earth. And if anyone thinks there will be no crime, I say, think again. The history of colonization is littered with crime. The US had its “wild west”, Australia its bushrangers, and the history of New Zealand has serious crime, the most spectacular being armed hold-ups of gold during the gold rush days. There will also be other opportunities for crime that are a little more sophisticated, such as in my novel “Red Gold

But there will also be serious commercial disagreements, particularly if some want to use something and others want to preserve it. I believe everyone has the right to their opinion, but there have to be rules and a means of enforcing them to avoid conflict. This procedure should be fully established beforeit is needed. There is plenty of time to argue now, but not in the middle of a dispute, and it is wrong to impose restrictions on an activity when huge sums of money have already been spent.

Oumuamua (1I) and Vega

Oumuamua is a small asteroidal object somewhere between 100 – 1000 meters long and is considerably longer than it is broad. Basically, it looks like a slab of rock, and is currently passing through the solar system on its way to wherever. It is our first observation of an interstellar object hence the bracketed formal name: 1 for first, I for interstellar. How do we know it came from interstellar space? Its orbit has been mapped, and its eccentricity determined. The eccentricity of a circular orbit is zero; an eccentricity greater than zero but less than one means the object is in an elliptical orbit, and the larger the eccentricity, the bigger the difference between closest and furthest approach to the sun. Oumuamua was found to have an eccentricity of 1.1995, which means, being greater than 1, it is on a hyperbolic orbit. It started somewhere where the sun’s gravity is irrelevant, and it will continue on and permanently leave the sun’s gravitational field. We shall never see it again, so the observation of it could qualify it for entry in “The Journal of Irreproducible Results”.

Its velocity in interstellar space (i.e.without the sun’s gravitational effects) was 26.3 km/s. We have no means of knowing where it came from, although if is trajectory is extrapolated backwards, it came from the direction of Vega. Of course it did not come from Vega, because when it passed through the space that Vega now occupies, Vega was somewhere else. Given there is no sign of ice on Oumuamua, which would form something like a cometary tail, it presumably came from the rocky zone closer to its system’s star, and this presumably has given rise to the web speculation that Oumuamua was some sort of alien space ship. Sorry, but no, it is not, and it does not need motors to enter interstellar space.

The way a body like Oumuamua could be thrown into interstellar space goes like this. There has to be a collision between two rocky bodies that are big enough to form fragments of the required size and the collision has to be violent enough to give the fragment a good velocity. That will also make a lot of dust. The fragments would be assumed to then go into elliptical orbits, but if there are both rocky planets and giants, the body could be ejected in the same way the Voyager space craft have left our solar system, namely through gravity assists. If the object is on the right trajectory it could get a gravity assist from an earth-like rocky planet, then another one from a giant that could give it enough impetus to leave the system. This presumably happened a long time ago, so we have no idea where the object came from.

Notwithstanding that, Oumuamua brought Vega to my attention, and it is, at least for me, an interesting star. That, of course, is because I have published a theory of planetary formation that is at odds with the generally accepted one. Vega has about twice the mass of the sun, and because it is bigger, it burns faster, and will have a life of about a billion years. It is roughly half-way through that, so it won’t have had time for planets to evolve intelligent life. The concentration of elements heavier than helium in Vega is about a third that of the sun. Vega also has an abnormally fast rate of rotation, so much so that it is about 88% of what would be required to start the star breaking up. This is significant because one of the oddities of our solar system is that the bulk of the angular momentum resides in the planets, while by far the bulk of the mass lies in the star. The implication might be that the lower level of heavier elements meant that Vega did not form cores fast enough and hence it does not have the giant planets of sufficient size to have taken up sufficient angular momentum. The situation could be like an ice skater who spins very fast, but slows the rotation by extending her arms. If the arms are very short, the spin cannot be slowed as much.

The infra-red emissions from Vega are consistent with a dust disk from about 70 – 100 A.U. out to 330 A.U. from the star (an A.U. is the distance from the sun to the Earth). This is assumed to have arisen from recent collisions of objects comparable to those in the Kuiper Belt here. There is apparently another dusty zone at 8 A.U., which would have to have originated from collisions between rocky objects. So far there is no evidence of planets around Vega, but equally there is no evidence there are none. We view Vega almost aligned with its axis of rotation, so most of the usual techniques for finding planets will not work. The transiting technique of the Kepler program requires us to be aligned with the ecliptic (which should be aligned with the equator) and the Doppler technique has similar limitations, although it has more tolerance for deviation. The Doppler technique detects the gravitational wobble of the star and if you could detect such a wobble directly, you could see it from along the polar axis. Unfortunately, we can’t, at least not yet, and worse, detecting such wobbles works best with very large planets around small stars. Here, if you follow my theory and accept the low metallicity, we expect small planets around a very large star. Direct observation has so far only worked for the first few million years of the star, where giant planets are radiating yellow to white light from their surface temperature that is so hot because of the gravitational accretion energy. These cool down reasonably quickly.

What grabbed my attention about Vega was the 8 A.U. dust zone. That can only be generated by a number of collisions because such dust zones have to be replenished. That is because solar radiation slows dust down, and it gradually falls into the star. So to have a good number of frequent collisions, you need a very large number of objects that could collide, which effectively requires a belt of boulders. So why have they not collided and formed a planet, when the standard theory of planetary formation says planets are formed by the collision of boulders to form planetesimals, and these collide to form embryos, which collide to form planets. In my ebook, “Planetary Formation and Biogenesis” I provide an answer, which is basically that to form rocky planets, the collisions have to happen in the accretion disk, and they happen very fast, and they happen because water vapour in the disk helps set cement. Once the accretion disk is removed, further accretion is impossible, other than from objects colliding with a big enough object for gravity to hold all the debris. Accordingly, collisions of boulder-sized objects or asteroids will make dust, and that would create a dust belt that would not last all that long. The equivalent of the Kuiper Belt around Vega appears to be between 3 – 6 times further out. In my theory, if the planet accreted in the same as the sun, it would be approximately 8 times further out. However, lower dust content may make it harder to radiate energy, hence accretion may be slower. If this second belt scales accordingly, it could correspond to our asteroid belt.  We know occasional collisions did occur in our asteroid belt because we see families of smaller fragments whose trajectories extrapolate back to a singe event. So maybe dust belts are tolerably common for short periods in the life of a star. It would not be a great coincidence we see one around Vega; there are a huge number of stars, we see a very large number of accretion disks, so dust belts should turn up sooner or later.

Finally, why does the star spin faster? Again, in my theory, the planets accrete from the solid and take their angular momentum, but then they also take angular momentum from the disk gas through a mechanism similar to the classical Magnus force. Vega has less dust to make planets, hence less angular momentum is taken that way, and because the planets should be smaller there is less gravity to take angular momentum from the gas, and more gas anyway. So the star retains a higher fraction of its angular momentum. All of this does not prove that my theory is right, but it is comforting that it at least has some sort of plausible support. If interested further, check out http://www.amazon.com/dp/B007T0QE6I.