Ebook Discount: A Face on Cydonia

From March 23 – 30, A Face on Cydonia,  the first in a series, will be discounted to 99c/99p on Amazon. On a TV program from Mars early in the 22nd century a battered butte on the Cydonia Mensae morphed into the classical face and winked. By 2129, following growing pressure suggesting a cover-up, Grigori Timoshenko forms an expedition to settle this “face” for once and for all. He recruits Fiona Bolton, a world expert in sonic viewing; Sharon Galloway, the developer of an AI digging device for a major corporation; also, Nathan Gill, a Martian settler. He has Jonathon Munro forced on him. Galloway hates Munro while Bolton hates corporates, so in a party with hidden agendas and with members hating each other, the gloss of visiting another planet soon wears thin. A story of corruption, greed, murder, the maverick, the nature of Mars, and with the problem of why would an alien race be interested in such a disparate party. Book 1 of the First Contact trilogy.

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What Happens Inside Ice Giants?

Uranus and Neptune are a bit weird, although in fairness that may be because we don’t really know much about them. Our information is restricted to what we can see in telescopes (not a lot) and the Voyager fly-bys, which, of course, also devoted a lot of attention to the Moons, since a lot of effort was devoted to images. The planets are rather large featureless balls of gas and cloud and you can only do so much on a “zoom-past”. One of the odd things is the magnetic fields. On Earth, the magnetic field axis corresponds with the axis of rotation, more or less, but not so much there. Earth’s magnetic field is believed to be due to a molten iron core, but that could not occur there. That probably needs explaining. The iron in the dust that is accreted to form planets is a fine powder; the particles are in the micron size. The Earth’s core arises because the iron formed lumps, melted, and flowed to the core because it is denser. In my ebook “Planetary Formation and Biogenesis” I argue that the iron actually formed lumps in the accretion disk. While the star was accreting, the region around where Earth is reached something like 1600 degrees C, above the melting point of iron, so it formed globs. We see the residues of that in the iron-cored meteorites that sometimes fall to Earth. However, Mars does not appear to have an iron core. Within that model, the explanation is simple. While on Earth the large lumps of iron flowed towards the centre, on Mars, since the disk temperature falls off with distance from the star, at 1.5 AU the large lumps did not form. As a consequence, the fine iron particles could not move through the highly viscous silicates, and instead reacted with water and oxidised, or, if you prefer, rusted.

If the lumps that formed for Earth could not form at Mars because it was too far away from the star, the situation was worse for Uranus. As with Mars, the iron would be accreted as a fine dust and as the ice giants started to warm up from gravitational collapse, the iron, once it got to about 500 degrees Centigrade, would rapidly react with the water and oxidise to form iron oxides and hydrogen. Why did that not happen in the accretion disk? Maybe it did, and maybe at Mars it was always accreted as iron oxides, but by the time it got to where Earth is, there would be at least ten thousand times more hydrogen than iron, and hot hydrogen reduces iron oxide to iron. Anyway, Uranus and Neptune will not have an iron core, so what could generate the magnetic fields? Basically, you need moving electric charge. The planets are moving (rotating) so where does the charge come from?

The answer recently proposed is superionic ice. You will think that ice melts at 0 degrees Centigrade, and yes, it does, but only at atmospheric pressure. Increase the pressure and it melts at a lower temperature, which is how you make snowballs. But ice is weird. You may think ice is ice, but that is not exactly correct. There appear to be about twenty ices possible from water, although there are controversial aspects because high pressure work is very difficult and while you get information, it is not always clear about what it refers to. You may think that irrespective of that, ice will be liquid at the centre of these planets because it will be too hot for a solid. Maybe.

In a recent publication (Nature Physics, 17, 1233-1238 November 2021) authors studied ice in a diamond anvil cell at pressures up to 150 GPa (which is about 1.5 million times greater than our atmospheric pressure) and about 6,500 degrees K (near enough to Centigrade at this temperature). They interpret their observations as there being superionic ice there. The use of “about” is because there will be uncertainty due to the laser heating, and the relatively short times up there. (Recall diamond will also melt.)

A superionic ice is proposed wherein because of the pressure, the hydrogen nuclei can move about the lattice of oxygen atoms, and they are the cause of the electrical conduction. These conditions are what are expected deep in the interior but not at the centre of these two planets. There will presumably be zones where there is an equilibrium between the ice and liquid, and convection of the liquid coupled with the rotation will generate the movement of charge necessary to make the magnetism. At least, that is one theory. It may or may not be correct.

Ebook Discount

From October 21 – 28, “Red Gold” will be discounted to 99c/99p.

Mars is to be colonized. The hype is huge, the suckers will line up, and we will control the floats. There is money to be made, and the beauty is, nobody on Earth can check what is really going on on Mars. Meanwhile, on Mars we shall be the only ones with guns. This can’t lose.

Except that there is one person who will try to stop the fraud. Which means he cannot be allowed to live. Partly inspired by the 1988 crash, Red Gold shows the anatomy of one sort of fraud. Then there is the problem that fraudsters with guns cannot permit anyone to expose them. One side must kill the other.

If you liked The Martian where science allowed one person to survive then Red Gold is a thriller that has a touch of romance, a little economics and enough science to show how Mars might be colonised and the colonists survive indefinitely.http://www.amazon.com/dp/B009U0458Y

Why Plate Tectonics?

How did plate tectonics start? Why has Earth got them and none of the rocky planets have, at least as far as we know? In my ebook “Planetary Formation and Biogenesis” my explanation as to one of the reasons for why plate tectonics are absent on Mars is that the Martian basaltic mantle appears to have about 17% iron oxide whle Earth has 7 – 11%. This means it cannot make eclogite whereas Earth’s basalt can. Eclogite is a particularly dense silicate and it is only made under serious pressure. 

To see the significance, we have to ask ourselves how plate tectonics works. The core generates hot spots, and hotter mantle material rises and has to push aside other rock, and we get what we call seafloor spreading, although it does not have to be underwater. The African rift valley is an example, in this case a relatively new example where the African plate is dividing, and eventually will have sea between Somalia and the Nubian zone. Similarly, the Icelandic volcanoes are due to “seafloor spreading”. Thus matter coming up pushes the surface plates aside, but then what? On Mars, the cold basalt has nowhere to go so it forms what is called a “stagnant lid”, and heat can only escape through volcanism. On Mars, this resulted in quite significant volcanism about three and a half billion years ago, then this more or less stopped, although not as much as some think because there is evidence of volcanic eruptions around Elysium within the last two million years. The net result is the “lid” gradually gets thicker, and stronger, which means the heat loss of the Martian mantle is actually much less than that of Earth.

On Earth, what happens is that as the basaltic plates get pushed aside, one goes under another, and this is where then eclogite becomes relevant. As the plate goes down, the increased pressure causes the basalt to form eclogite, and because it is denser than its surroundings, gravity makes it go deeper. It is this pull subduction that keeps plate tectonics going.

So, what about Venus? The usual answer is that Venus had a stagnant lid, but at certain intervals the internal heat is so great there is a general overturn and there is a general resurfacing. However, maybe that is not exactly correct. Our problem with Venus is we cannot see the surface thanks to the clouds. The best we can manage is through radar, and recent (June, 2021) information has provided some surprises (Byrne, et al.,   https://doi.org/10.1073/pnas.2025919118).  Basically, what was found was evidence that many of the lowlands had broken into crustal blocks and these blocks are moving relative to each other, in the same way as pack ice moves. The cause would be mantle convection that stresses the crust. The Venusian crust has many landforms, including thin belts where crust has been pushed together to form ridges, or pulled apart to form troughs. However, these ones tend to encompass low-lying regions that are not deformed, but rather appear to be individual blocks that shift, rotate and slide past each other. The authors suggest this what Earth was like before plate tectonics got going.

As to why they started here and not there has no obvious answer. The fact that Earth rotates far more quickly will generate much stronger Coriolis forces. It may be that the absence of water on Venus removes a potential lubricant, but that seems unlikely if blocks of crust are moving. My personal view is that one key point is it needs something to force the crust downwards. Eclogite may pull it down, but something has to push the basalt down to force it to make eclogite. My guess here is that Earth has one thing the other rocky planets do not have: granitic continents. Granite floats on basalt, so if a basaltic mass was pushed against a significant granitic mass, the granite would slide over the top and its weight would push the basalt down. When it made eclogite, the denser basalt would continue its downward motion, pulling a plate with it. Is that right? Who knows, but at least it looks plausible to me.

A Discovery on Mars

Our space programs now seem to be focusing in the increasingly low concentrations or more obscure events, as if this will tell us something special. Recall earlier there was the supposed finding of phosphine in the Venusian atmosphere. Nothing like stirring up controversy because this was taken as a sign of life. As an aside, I wonder how many people actually have ever noticed phosphine anywhere? I have made it in the lab, but that hardly counts. It is not a very common material, and the signal in the Venusian atmosphere was almost certainly due to sulphur dioxide. That in itself is interesting when you ask how would that get there? The answer is surprisingly simple: sulphuric acid is known to be there, and it is denser, and might form a fog or even rain, but as it falls it hits the hotter regions near the surface and pyrolysis to form sulphur dioxide, oxygen and water. These rise, the oxygen reacts with sulphur dioxide to make sulphur trioxide (probably helped by solar radiation), which in turn reacts with water to form sulphuric acid, which in turn is why the acid stays in the atmosphere. Things that have a stable level on a planet often have a cycle.

In February this year, as reported in Physics World, a Russian space probe detected hydrogen chloride in the atmosphere of Mars after a dust storm occurred. This was done with a spectrometer that looked at sunlight as it passed through the atmosphere, and materials such as hydrogen chloride would be picked up as a darkened line at the frequency for the bond vibration in the infrared part of the spectrum. The single line, while broadened due to rotational options, would be fairly conclusive. I found the article to be interesting for all sorts of reasons, one of which was for stating the obvious. Thus it stated that dust density was amplified in the atmosphere during a global dust storm. Who would have guessed that? 

Then with no further explanation, the hydrogen chloride could be generated by water vapour interacting with the dust grains. Really? As a chemist my guess would be that the dust had wet salt on it. UV radiation and atmospheric water vapour would oxidise that, to make at first sodium hypochlorite, like domestic bleach and then hydrogen.  From the general acidity we would then get hydrogen chloride and probably sodium carbonate dust. They were then puzzled as to how the hydrogen chloride disappeared. The obvious answer is that hydrogen chloride would strongly attract water, which would form hydrochloric acid, and that would react with any oxide or carbonate in the dust to make chloride salts. If that sounds circular, yes it is, but there is a net degradation of water; oxygen or oxides would be formed, and hydrogen would be lost to space. The loss would not be very great, of course, because we are talking about parts per billion in a highly rarefied upper atmosphere and only during a dust storm.

Hydrogen chloride would also be emitted during volcanic eruptions, but that is probably able to be eliminated here because Mars no longer has volcanic eruptions. Fumarole emissions would be too wet to get to the upper atmosphere, and if they occurred, and there is no evidence they still do, any hydrochloric acid would be expected to react with oxides, such as the iron oxide that makes Mars look red, rather quickly.  So the unfortunate effect is that the space program is running up against the law of diminishing returns. We are getting more and more information that involves ever-decreasing levels of importance. Rutherford once claimed that physics was the only science – the rest was stamp collecting.  Well, he can turn in his grave because to me this is rather expensive stamp collecting.

Where are the Planets that Might Host Life?

In the previous posts I showed why RNA was necessary for primitive life to reproduce, but the question then is, what sort of planets will have the necessary materials? For the rocky planets, once they reached a certain size they would attract gas gravitationally, but this would be lost after the accretion disk was removed by the extreme UV put out by the new star. Therefore all atmosphere and surface water would be emitted volcanically. (Again, for the purposes of discussion, volcanic emission includes all geothermal emissions, e.g. from fumaroles.) Gas could be adsorbed on dust as it was accreted, but if it were, because heats of adsorption of the gases other than water are very similar, the amount of nitrogen would roughly equal the amount of neon. It doesn’t. (Neon is approximately at the same level as nitrogen in interstellar gas.)

The standard explanation is that since the volatiles could not have been accreted, they were delivered by something else. The candidates: comets and carbonaceous asteroids. Comets are eliminated because their water contains more deuterium than Earth’s water, and if they were the source, there would be twenty thousand times more argon. Oops. Asteroids can also be eliminated. At the beginning of this century it was shown that various isotope ratios of these bodies meant they could not be a significant source. In desperation, it was argued they could, just, if they got subducted through plate tectonics and hence were mixed in the interior. The problem here is that neither the Moon nor Mars have subduction, and there is no sign of these objects there. Also, we find that the planets have different atmospheres. Thus compared to Earth, Venus has 50% more carbon dioxide (if you count what is buried as limestone on Earth), four times more nitrogen, and essentially no water, while Mars has far less volatiles, possibly the same ratio of carbon dioxide and water but it has far too little nitrogen. How do you get the different ratios if they all came from the same source? It is reasonably obvious that no single agent can deliver such a mix, but since it is not obvious what else could have led to this result, people stick with asteroids.

There is a reasonably obvious alternative, and I have discussed the giants, and why there can be no life under-ice on Europa https://wordpress.com/post/ianmillerblog.wordpress.com/855) and reinforced by requirement to join ribose to phosphate. The only mechanism produced so far involves the purine absorbing a photon, and the ribose transmitting the effect. Only furanose sugars work, and ribose is the only sugar with significant furanose form in aqueous solution. There is not sufficient light under the ice. There are other problems for Europa. Ribose is a rather difficult sugar to make, and the only mechanism that could reasonably occur naturally is in the presence of soluble silicic acid. This requires high-temperature water, and really only occurs around fumaroles or other geothermal sites. (The terrace formations are the silica once it comes out of solution on cooling.)

So, where will we find suitable planets? Assuming the model is correct, we definitely need the dust in the accretion disk to get hot enough to form carbides, nitrides, and silicates capable of binding water. Each of those form at about 1500 degrees C, and iron melts at a bit over this temperature, but it can be lower with impurities, thus grey cast is listed as possible at 1127 degrees C. More interesting, and more complicated, are the silicates. The calcium aluminosilicates have a variety of phases that should separate from other silicate phases. They are brittle and can be easily converted to dust in collisions, but their main feature is they absorb water from the gas stream and form cements. If aggregation starts with a rich calcium aluminosilicate and there is plenty of it, it will phase separate out and by cementing other rocks and thus form a planet with plenty of water and granitic material that floats to the surface. Under this scene, Earth is optimal. The problem then is to get this system in the habitable zone, and unfortunately, while both the temperatures of the accretion disk and the habitable zone depend on the mass of the star, they appear to depend on different functions. The net result is the more common red dwarfs have their initial high-temperature zone too close to the star, and the most likely place to look for life are the G- and heavy K-type stars. The function for the accretion disk temperature depends on the rate of stellar accretion, which is unknown for mature stars but is known to vary significantly for stars of the same mass, thus LkCa 15b is three times further away than Jupiter from an equivalent mass star. Further, the star must get rid of its accretion disk very early or the planets get too big. So while the type of star can be identified, the probability of life is still low.

How about Mars? Mars would have been marginal. The current supply of nitrogen, including what would be lost to space, is so low life could not emerge, but equally there may be a lot of nitrogen in the solid state buried under the surface. We do not know if we can make silicic acid from basalt under geochemical conditions and while there are no granitic/felsic continents there, there are extrusions of plagioclase, which might do. My guess is the intermittent periods of fluid flow would have been too short anyway, but it is possible there are chemical fossils there of what the path towards life actually looked like. For me, they would be of more interest than life itself.

To summarise what I have proposed:

• Planets have compositions dependent on where they form
• In turn, this depends on the temperatures reached in the accretion disk
• Chemicals required for reproduction formed at greater than 1200 degrees C in the accretion disk, and possibly greater than 1400 degrees C
• Nucleic acids can only form, as far as we know, through light
• Accordingly, we need planets with reduced nitrogen, geothermal processing, and probably felsic/granitic continents that end in the habitable zone.
• The most probable place is around near-earth-sized planets around a G or heavy K type star
• Of those stars, only a modest proportion will have planets small enough

Thus life-bearing planets around single stars are likely to be well-separated. Double stars remain unknown quantities regarding planets. This series has given only a very slight look at the issues. For more details, my ebook Planetary Formation and Biogenesis(http://www.amazon.com/dp/B007T0QE6I) has far more details.

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 Mining

Most readers will have heard that there are a number of proposals to go mine asteroids, or maybe Mars. The implication is that Earth will become short of resources, so we can mine things in space. However, if we mine there for the benefit here, how would we get such resources here, and in what form. If the resources are refined elsewhere, then there is the “simple” cost of getting them here. If we bring them down in a shuttle, we have to get the shuttle back up there, and the cost is huge. If on the other hand, we drop them (and gravity is cheap) we have to stop whatever we send from burning up in the atmosphere, so to control the system we have to build some sort of spacecraft out there to bring them down. Overall, this is unlikely to be profitable. On the other hand if we build structures in space, such as space stations, or on Mars for settlers, then obviously it is very much cheaper to use local resources, if we can refine them there.

So, what are the local resources? The answer is it depends on the history. All the solid elements are expelled in novae (light elements only) or supernovae (all). The very light elements lithium, beryllium and boron are rather rare because they tend to be destroyed in the star before the explosion. The elements vary in relative amounts made, and basically the heavier the element the less is made, and elements with an even number of protons are more common than elements with odd numbers. Iron, and to some extent nickel, are more common than those around them because the nuclei are particularly stable. The most common elements are magnesium, silicon and with iron about 10% less. Sulphur is about half as common, calcium and aluminium are about 6 – 8% as common as silicon, while the metals such as copper and zinc are about 100,000 times less common than aluminium. The message from all that is that unless there is some process that has sorted the various elements, an object in space is likely to have the composition of dust, which are mainly silicates, i.e. rock. There may well be metal sulphides as well, as there is a lot of sulphur there.

So what sorting could there be? The most obvious is that if the body formed close enough to the star during primary accretion, the heat in the accretion disk could be sufficient to melt the element, if it were there as an element. It appears that iron was, because we get iron meteorites and iron-cored meteorites. The accretion disk, of course, was primarily hydrogen, and at the melting point of iron, hydrogen will reduce iron oxides to iron, also making water. So we could expect asteroids to have iron cores? Well, we are sure most members of the asteroid belt do not, and the reason why not is presumably it did not get hot enough to melt iron where they formed. However, since the regolith (fine “soil”) on the Moon has iron dust in it, perhaps there was iron dust where the asteroids formed. However, the problem is what caused them to solidify. If they melted, steam would be created, and that would oxidise iron dust, so the iron then would be as an oxide, or a silicate.

The ores we have on Earth are there due to geochemical processing. For example, in the mantle, water forms a supercritical fluid that dissolves all sorts of things, including silica and gold. When this comes to the surface, it cools and deposits its solids, which is why gold is found in some quartz veins. The big iron oxide deposits we have were formed through carbon dioxide weathering iron-containing silicates (such as olivine and pyroxene) to make ferrous and magnesium solutions in the oceans. When oxygen came along, the ferrous precipitated to form goethite and haematite, which we now mine. All the ore deposits on Earth are there because of geochemical processing.

There will be limited such processing on Mars, and on the Moon. Thus on the Moon, as it cooled some materials crystallised out before others. The last to crystallise on the Moon was what we call KREEP, which stands for potassium, rare earths and phosphate, which is what it largely comprises. There is also anorthite, a calcium aluminosilicate on the Moon. As for Mars, it seems to be mainly basaltic, which means it is mainly iron magnesium silicate. The other elements will be there, of course, mixed up, but how do you get them out? Then there is the problem of chemical compatibility. Suppose you want rare earths? The rare earths are not that rare, actually, and are about as common as copper. But copper occurs in nice separate ores, at least on Earth, but rare earths have chemical properties somewhat similar to aluminium. For every rare earth atom, there are 100,000 aluminium atoms, all behaving similarly, although not exactly the same. So it is far from easy to separate them from the aluminium, then there is the problem of separating them from each other.

There is what I consider a lot of nonsense spoken about asteroids. Thus one was reported to be “mainly diamond”. On close questioning, it had an infrared signature typical of carbon. That would be typically amorphous graphitic carbon, and no, they did not know specifically it was diamond. Another proposal was to mine asteroids for iron. There may well be some with an iron core, and Vesta probably does have such a core, but most do not. I have heard some say there will be lots of platinum there. Define lots, because unless there has been some form of sorting, it will be there proportionately to its dust concentration, and while there is more than in most bits of basalt, there will still be very little. In my opinion, beware of investment opportunities to get rich quickly through space mining.

Book Discount

From February 14 – 21, (Seattle time) “Red Gold” will be discounted to 99c/99p. In the previous post, I gave a rather frivolous scam possibility related to space exploration. Try something a little more serious.

 

Mars is to be colonized. The hype is huge, the suckers will line up, and we will control the floats. There is money to be made, and the beauty is, nobody on Earth can check what is really going on on Mars.

Partly inspired by the 1988 crash, Red Gold shows the anatomy of one sort of fraud. Then there’s Mars, and where The Martian showed the science behind one person surviving for a modest period, Red Gold shows the science needed for many colonists to survive indefinitely. As a bonus there is an appendix that shows how the writing of this novel led to a novel explanation for the presence of Martian rivers.

If you liked The Martian where science allowed one person to survive then Red Gold is a thriller that has a touch of romance, a little economics and enough science to show how Mars might be colonised and the colonists survive indefinitely.

http://www.amazon.com/dp/B009U0458Y

Origin of the Rocky Planet Water, Carbon and Nitrogen

The most basic requirement for life to start is a supply of the necessary chemicals, mainly water, reduced carbon and reduced nitrogen on a planet suitable for life. The word reduced means the elements are at least partly bound with hydrogen. Methane and ammonia are reduced, but so are hydrocarbons, and aminoacids are at least partly reduced. The standard theory of planetary formation has it (wrongly, in my opinion) that none of these are found on a rocky planet and have to come from either comets, or carbonaceous asteroids. So, why am I certain this is wrong? There are four requirements that must be met. The first is, the material delivered must be the same as the proposed source; the second is they must come in the same proportions, the third is the delivery method must leave the solar system as it is now, and the fourth is that other things that should have happened must have.

As it happens, oxygen, carbon, hydrogen and nitrogen are not the same through the solar system. Each exists in more than one isotope (different isotopes have different numbers of neutrons), and the mix of isotopes in an element varies in radial distance from the star. Thus comets from beyond Neptune have far too much deuterium compared with hydrogen. There are mechanisms by which you can enhance the D/H ratio, such as UV radiation breaking bonds involving hydrogen, and hydrogen escaping to space. The chemical bonds to deuterium tend to be several kJ/mol. stronger than bonds to hydrogen. The chemical bond strength is actually the same, but the lighter hydrogen has more zero point energy so it more easily breaks and gets lost to space. So while you can increase the deuterium to hydrogen ratio, there is no known way to decrease it by natural causes. The comets around Jupiter also have more deuterium than our water, so they cannot be the source. The chondrites have the same D/H ratio as our water, which has encouraged people to believe that is where our water came from, but the nitrogen in the chondrites has too much 15N, so it cannot be the source of our nitrogen. Further, the isotope ratios of certain heavy elements such as osmium do not match those on Earth. Interestingly, it has been argued that if the material was subducted and mixed in the mantle, it would be just possible. Given that the mantle mixes very poorly and the main sources of osmium now come from very ancient plutonic extrusions, I have doubts on that.

If we look at the proportions, if comets delivered the water or carbon, we should have five times more nitrogen, and twenty thousand times more argon. Comets from the Jupiter zone get around this excess by having no significant nitrogen or argon, and insufficient carbon. For chondrites, there should be four times as much carbon and nitrogen to account for the hydrogen and chlorine on Earth. If these volatiles did come from chondrites, Earth has to be struck by at least 10^23 kg of material (that is, ten followed by 23 zeros). Now, if we accept that these chondrites don’t have some steering system, based on area the Moon should have been struck by about 7×10^21 kg, which is approximately 9.5% of the Moon’s mass. The Moon does not subduct such material, and the moon rocks we have found have exactly the same isotope ratios as Earth. That mass of material is just not there. Further, the lunar anorthosite is magmatic in origin and hence primordial for the Moon, and would retain its original isotope ratios, which should give a set of isotopes that so not involve the late veneer, if it occurred at all.

The third problem is that we are asked to believe that there was a narrow zone in the asteroid belt that showered a deluge of asteroids onto the rocky planets, but for no good reason they did not accrete into anything there, and while this was going on, they did not disturb the asteroids that remain, nor did they disturb or collide with asteroids closer to the star, which now is most of them. The hypothesis requires a huge amount of asteroids formed in a narrow region for no good reason. Some argue the gravitational effect of Jupiter dislodged them, but the orbits of such asteroids ARE stable. Gravitational acceleration is independent of the body’s mass, and the remaining asteroids are quite untroubled. (The Equivalence Principle – all bodies fall at the same rate, other than when air resistance applies.)

Associated with this problem is there is a number of elements like tungsten that dissolve in liquid iron. The justification for this huge barrage of asteroids (called the late veneer) is that when Earth differentiated, the iron would have dissolved these elements and taken them to the core. However, they, and iron, are here, so it is argued something must have brought them later. But wait. For the isotope ratios this asteroid material has to be subducted; for them to be on the continents, they must not be subducted. We need to be self-consistent.

Finally, what should have happened? If all the volatiles came from these carbonaceous chondrites, the various planets should have the same ratio of volatiles, should they not? However, the water/carbon ratio of Earth appears to be more than 2 orders of magnitude greater than that originally on Venus, while the original water/carbon ratio of Mars is unclear, as neither are fully accounted for. The N/C ratio of Earth and Venus is 1% and 3.5% respectively. The N/C ratio of Mars is two orders of magnitude lower than 1-2%. Thus if the atmospheres came from carbonaceous chondrites:

Only the Earth is struck by large wet planetesimals,

Venus is struck by asteroidal bodies or chondrites that are rich in C and especially rich in N and are approximately 3 orders of magnitude drier than the large wet planetesimals,

Either Earth is struck by a low proportion of relatively dry asteroidal bodies or chondrites that are rich in C and especially rich in N and by the large wet planetesimals having moderate levels of C and essentially no N, or the very large wet planetesimals have moderate amounts of carbon and lower amounts of nitrogen as the dry asteroidal bodies or chondrites, and Earth is not struck by the bodies that struck Venus,

Mars is struck only infrequently by a third type of asteroidal body or chondrite that is relatively wet but is very nitrogen deficient, and this does not strike the other bodies in significant amounts,

The Moon is struck by nothing,

See why I find this hard to swallow? Of course, these elements had to come from somewhere, so where? That is for a later post. In the meantime, see why I think science has at times lost hold of its methodology? It is almost as if people are too afraid to go against the establishment.