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.

Advertisements

Martian Fluvial Flows, Placid and Catastrophic

Image

Despite the fact that, apart localized dust surfaces in summer, the surface of Mars has had average temperatures that never exceeded about minus 50 degrees C over its lifetime, it also has had some quite unexpected fluid systems. One of the longest river systems starts in several places at approximately 60 degrees south in the highlands, nominally one of the coldest spots on Mars, and drains into Argyre, thence to the Holden and Ladon Valles, then stops and apparently dropped massive amounts of ice in the Margaritifer Valles, which are at considerably lower altitude and just north of the equator. Why does a river start at one of the coldest places on Mars, and freeze out at one of the warmest? There is evidence of ice having been in the fluid, which means the fluid must have been water. (Water is extremely unusual in that the solid, ice, floats in the liquid.) These fluid systems flowed, although not necessarily continuously, for a period of about 300 million years, then stopped entirely, although there are other regions where fluid flows probably occurred later. To the northeast of Hellas (the deepest impact crater on Mars) the Dao and Harmakhis Valles change from prominent and sharp channels to diminished and muted flows at –5.8 k altitude that resemble terrestrial marine channels beyond river mouths.

So, how did the water melt? For the Dao and Harmakhis, the Hadriaca Patera (volcano) was active at the time, so some volcanic heat was probably available, but that would not apply to the systems starting in the southern highlands.

After a prolonged period in which nothing much happened, there were catastrophic flows that continued for up to 2000 km forming channels up to 200 km wide, which would require flows of approximately 100,000,000 cubic meters/sec. For most of those flows, there is no obvious source of heat. Only ice could provide the volume, but how could so much ice melt with no significant heat source, be held without re-freezing, then be released suddenly and explosively? There is no sign of significant volcanic activity, although minor activity would not be seen. Where would the water come from? Many of the catastrophic flows start from the Margaritifer Chaos, so the source of the water could reasonably be the earlier river flows.

There was plenty of volcanic activity about four billion years ago. Water and gases would be thrown into the atmosphere, and the water would ice/snow out predominantly in the coldest regions. That gets water to the southern highlands, and to the highlands east of Hellas. There may also be geologic deposits of water. The key now is the atmosphere. What was it? Most people say it was carbon dioxide and water, because that is what modern volcanoes on Earth give off, but the mechanism I suggested in my “Planetary Formation and Biogenesis” was the gases originally would be reduced, that is mainly methane and ammonia. The methane would provide some sort of greenhouse effect, but ammonia on contact with ice at minus 80 degrees C or above, dissolves in the ice and makes an ammonia/water solution. This, I propose, was the fluid. As the fluid goes north, winds and warmer temperatures would drive off some of the ammonia so oddly enough, as the fluid gets warmer, ice starts to freeze. Ammonia in the air will go and melt more snow. (This is not all that happens, but it should happen.)  Eventually, the ammonia has gone, and the water sinks into the ground where it freezes out into a massive buried ice sheet.

If so, we can now see where the catastrophic flows come from. We have the ice deposits where required. We now require at least fumaroles to be generated underneath the ice. The Margaritifer Chaos is within plausible distance of major volcanism, and of tectonic activity (near the mouth of the Valles Marineris system). Now, let us suppose the gases emerge. Methane immediately forms clathrates with the ice (enters the ice structure and sits there), because of the pressure. The ammonia dissolves ice and forms a small puddle below. This keeps going over time, but as it does, the amount of water increases and the amount of ice decreases. Eventually, there comes a point where there is insufficient ice to hold the methane, and pressure builds up until the whole system ruptures and the mass of fluid pours out. With the pressure gone, the remaining ice clathrates start breaking up explosively. Erosion is caused not only by the fluid, but by exploding ice.

The point then is, is there any evidence for this? The answer is, so far, no. However, if this mechanism is correct, there is more to the story. The methane will be oxidised in the atmosphere to carbon dioxide by solar radiation and water. Ammonia and carbon dioxide will combine and form ammonium carbonate, then urea. So if this is true, we expect to find buried where there had been water, deposits of urea, or whatever it converted to over three billion years. (Very slow chemical reactions are essentially unknown – chemists do not have the patience to do experiments over millions of years, let alone billions!) There is one further possibility. Certain metal ions complex with ammonia to form ammines, which dissolve in water or ammonia fluid. These would sink underground, and if the metal ions were there, so might be the remains of the ammines now. So we have to go to Mars and dig.

 

 

 

 

 

Settling Mars and High Energy Solar Particles

Recently, the US government announced that sending people to Mars was a long-term objective, and accordingly it is worth looking at some of the hazards. One that often gets airing is the fact that the sun sends out bursts of high-energy particles that are mainly protons, i.e. hydrogen atoms with their electrons stripped off. If these strike living matter, they tend to smash the molecules, as they have energy far greater than the energy of the chemical bond. These are of little hazard to us usually, though, because they are diverted by the earth’s magnetic field. It is this solar wind that is the primary cause of auroras. The solar wind particles knock electrons out of gas molecules, and the light is generated when electrons return. As you might guess, if these particles can knock out enough electrons from molecules to generate that light show, the particle flux would be quite undesirable for DNA, and a high cancer rate would be expected if some form of protection could not be provided.

The obvious method is to divert the particles, and electromagnetism provides a solution. When a charged particle is moving and it strikes a magnetic field, there is a force that causes the path of the charged particle to bend. The actual force is calculated through something called a vector cross product, but in simple terms the bending force increases with the velocity of the particle, the strength of the magnetic field, and the angle between the path and the magnetic field. The force is maximum when the path is at right angles to the magnetic field, and is actually zero when the particle motion is parallel to the field. The question then is, can we do anything about the solar particles with this?

The first option would be to generate a magnetic field in Mars. Unfortunately, that is not an option, because we have no idea how to generate a dynamo within the planet, nor do we know if it is actually possible. The usual explanation for the earth’s magnetic field is that it is generated through the earth’s rotation and the iron core. Obviously, there is more to it than that, but one thing we know is that the density of Mars is about 3.9 whereas Earth is about 5.5. Basalt, the most common mix of metal silicates, has a density ranging from 3 to 3.8, but of course density also increases with compression. This suggests that Mars does not have much of an iron core. As far as I am aware, it is also unclear whether the core of Mars is solid or liquid. Accordingly, it appears clear there is no reasonable hope of magnetizing Mars.

The alternative is to put an appropriate magnetic field on the line between Mars and the sun. To do that, we have to put a properly aligned strong magnetic field between Mars and the sun. The problem is, bodies orbiting the sun generally only have the same angular rotation about the sun as Mars if they are at the same distance from the sun as Mars, or on average if they are orbiting Mars, in which case they cannot be between, and if they are not between all the time, they are essentially useless.

However, for the general case where a medium sized body orbits a much larger one, such as a planet around a star, or the Moon around Earth, there are five points where a much smaller object can orbit in a fixed configuration with respect to the other two. These are known as Lagrange points, named after the French mathematician who found them, and the good news is that L1, the first such point, lies directly between the planet and the star. Thus on Mars, a satellite at L1 would always seem to “eclipse” the sun, although of course it would be too small to be noticed.

Accordingly, a solution to the problem of high-energy solar particles on settlers on Mars would be to put a strong enough magnetic field at the Mars sun L1 position, so as to bend the path of the solar particles away from Mars. What is interesting is that very recently Jim Green, NASA Planetary Science Division Director, made a proposal of putting such a magnetic shield at the Mars-Sun-L1 position. For a summary of Green’s proposal, see http://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/ .

The NASA proposal was focused more on reducing the stripping of the atmosphere by the solar wind. If so, according to Green, such a shield could help Mars achieve half the atmospheric pressure of Earth in a matter of years, on the assumption that frozen CO2 would sublimate, thus starting the process of terraforming. I am not so sure of that, because stopping radiation hitting Mars should not lead to particularly rapid sublimation. It is true that stopping such charged particles would help in stopping gas being knocked off the outer atmosphere, but the evidence we have is that such stripping is a relatively minor effect.

The other point about this is that I made this suggestion in my ebook novel Red Gold, published in 2011, which is about the colonization of Mars. My idea there was to put a satellite at L1 with solar panels and superconducting magnets. If the magnet coils can be shielded from sunlight, even the high temperature superconductors we have now should be adequate, in which case no cooling might be required. Of course the novel is science fiction, but it is always good to see NASA validate one of your ideas, so I am rather pleased with myself.

Water on Mars!

Just after I write a blog on “The Martian”, NASA announces evidence for flowing water on Mars. Yes, the announcement probably was to spark some interest in NASA from the film Matt Damon is going to star in. The evidence seems to depend (and I have yet to see the relevant scientific papers) on some gullies carved in the side of one crater that grow when the temperatures are higher, and these gullies are best described in terms of water flow. The temperature of Mars is below the freezing point of water, and the air pressure is about half that needed for liquid water to exist, so how can this be? Where did this water come from?
There are various theories, one of them being there are underground aquifers where water flows, and these come to the surface. On a personal level, I cannot see this as being likely. An underground aquifer would still need heat to melt the water, and while there might be geochemical heat, why is this heat around craters? Actually, there are a number of craters on Mars that show signs of ancient water flow, and the usual explanation for these is that when the impact occurred, the heat of the impact melted any ice that was around, and this water was available to emerge from time to time, until it froze again. Various calculations suggest liquid water could be available from such impact heating for up to 50,000 years. However, if this were a new crater, and I understand it is not, we would still expect the water to emerge from anywhere along the side or bottom of the crater, and not specifically from near the top.
The most likely explanation I can come up with is that the water comes from the atmosphere. Actually, the atmosphere is quite humid; about 50%, and every now and again we even see cirrus clouds on Mars. The basic problem is that there is not very much air anyway. But, back to the question, how does water flow on Mars?
First, if you dissolve something else in water, the melting point is lowered, so this water is almost certainly a strong solution of something in water. Further, if you dissolve something in water, the boiling point is raised, or alternatively, the vapour pressure is lowered, by an amount dependent on how much solid is in the water. This is likely to be part of the answer, because there appears to be one new piece of information in the announcement. The gullies are not new, nor is the argument that they are caused by water flow, and I had references to that in my survey of information in Planetary Formation and Biogenesis, which was published as an ebook some years ago. No, what is new here is that there is spectral evidence for perchlorates in the bottom of the crater.
What seems to happen on Mars is that chlorides, which are rather common if water can concentrate them (the sea has quite a bit of sodium chloride), are oxidized, thanks to the hard ultraviolet radiation, to perchlorates. Magnesium perchlorate is deliquescent, that is, it sucks water out of the atmosphere and dissolves itself in it, and the melting point of the solutions will be quite lower. I don’t know what it would be, but calcium chloride, which is also deliquescent, when mixed with ice, melts the ice and lowers the temperatures to about minus 40 degrees. Magnesium perchlorate would probably do something similar.
What does that mean for life on Mars? As far as I am concerned, there is no change, and it might have got harder, the reason being that perchlorates are strong oxidizing agents, and may well interfere with certain life functions. Further, the solutions are saltier than “The Dead Sea”, and as the name suggests, it is not brimming with life.
This method of getting fluid water might also be thought to solve the problem of how to “make water” in the book, and presumably the film, “The Martian”. All you have to do is to distill off the water, then reuse the perchlorate. My personal view is this would be far too slow, and to get water, in my novel Red Gold I suggested simply pumping up the air pressure and squeezing/chilling the water out. Even better is finding ice, although that might be easier said than done in an emergency. So, while this announcement really makes little difference to the likelihood of finding life on Mars, it does make the chances of settling on Mars and surviving a little better.

Materials for the first Martian settlers

In the previous post, I discussed the difficulties settlers on Mars might have with making things to construct domes, etc in which to grow food. Now, let’s suppose they have got that under control, where are the next difficulties? The settlers have a place to live, they have grown food in their domes, but they still have to cook it. Yes, we have energy (assuming all has gone well) but there are other things as well, assuming the settlers want more than the ability to survive. For example, in cooking there is often a lipid, such as olive oil or butter used. Even assuming they have big enough domes, are they going to wait around for olive trees to grow? Fortunately there is a way out of this. Microalgae have lipids in them, and if we grow them then mature them in a nutrient deficient solution, the oil content can rise to over 60% by weight. If there are plenty of nutrients, then the microalgae grow very rapidly (more rapidly than most plants) and largely contain protein, which makes them a desirable food, but for two things: the taste, and the fact they have a rather high content of nucleic acids. In my novel Red Gold, set in a proposed colonization of Mars, I suggested there would be a variety developed with much lower nucleic acid content. I suggested the settlers would start off by eating a lot of chlorella because it takes a long time for plants to grow.

Another problem the settlers will have involves clothing. Clothing is made from fibres and most fibres now come from the oil industry. Of course we can get free of synthetic fibres by returning to cotton and linen, which come from plants, as long as someone remembers to take them. But if settlers are going to do that, they will be growing a lot more than they are eating. Wool would not be available in most scenarios because sheep need a significant area to graze on, and that means building giant domes, AND finding enough material to make soil. Eventually, as they start growing crops, the dead waste plant material will be used to make more soil, but it will be gradual. Soil means more than “dirt”. Then, after that, they will still need polymers from the chemical industry to make suits that can be used for going outside, because it is important to be able to seal the air in the zone in which you intend to breathe. Where do they get the raw materials for such polymers? They will have to take something that will generate them. As it happens, chlorella can be processed to help make some such polymers.

Speaking of dirt, settlers may want to wash. Yes, you can wash in just water, to some degree of efficiency, but you might want soap. Can they make that there? Soap is made by treating lipids with caustic soda, whereupon you make soap and glycerol. Needless to say, you have to get the ratio of caustic soda right. Interestingly, pioneers often did this on Earth. I can recall as a boy, my father elected to do what his father had done, and make soap in the back garden. The family carefully kept the fact from roasts, clarified it, and it was heated up in a kerosine tin (4 gallons) in the back yard, then the caustic soda was added. This was largely used for laundry. The point is, soap making is not difficult, although it is more so if you want quality. But this brings up another point: when settlers get to Mars, they will have to do just about everything themselves, and unlike pioneers on Earth, there is no grass ranges, nor forests for timber. Worse, many of the things we take for granted involve several steps. Even for soap, the settlers first have to find and mine salt, then they have electrolyse that (doing something with the chlorine that is also made) then they have to react that with lipids that have been collected and purified, then they have to separate out the glycerol and do one or tow things to make an attractive cake. Most things we take for granted have a lot more steps, each requiring a specific skill. There are just so many things to do that involve a lot of different skills that you need a reasonably large number of people to do them. But then you have to take an awful lot of stuff to sustain all these settlers while they get going.

Perhaps now you see the trend of what I am trying to say. The cost of lifting stuff from Earth into space is horrendous, so settlers on Mars simply could not afford to purchase anything other than the most valuable materials from Earth. They have to make everything they want there, except possibly the most valuable pharmaceuticals, and there are very few raw materials that are easily obtained there. Life for such a settler would be extremely spartan, and it will not work unless there are a number of skilled people to carry out the tasks that require advanced technology.

Solstice Promo Special

And now, a quick commercial break! Four of my fictional ebooks are on special at Amazon from the solstice for a few days, including the one that was actually the cause of my developing my alternative theory of planetary formation. The fiction required an unusual discovery on Mars, I invented one, and an editor had the cheek to say it was unbelievable. Now editors in publishing houses have a right to criticize grammar, but not science, so I ended up determined to do something about this. So, to celebrate/get over the midwinter solstice (our Saturnalia!) there are significant rice reductions on these novels.

Specific details:

On June 21 my four “Mars novels” are price reduced to 99c on Amazon.com, and 99p on Amazon UK. The prices gradually increase through to June 27. The ebooks are:

Red Gold: the colonization of Mars, which gives the opportunity for a stockmarket fraud. Also possibly unique in that the writing of this led to an original scientific theory (outlined in an appendix). http://www.amazon.com/dp/B009U0458Y

Then the “First Contact” trilogy.

A Face on Cydonia: a small number of mutually incompatible people form an expedition to find out for once and for all whether the “Face” is an alien monument, and they each find exactly what they do not want. Also an outline of a future economy starved of resources. http://www.amazon.com/dp/B00BQPUG6Q

Dreams Defiled: One member of the party, who received the Greek gift, sets out to ensure that nobody else thrives. http://www.amazon.com/dp/B00D0HOV5A

Jonathon Munros: A tale of revenge, and unintended consequences, including self-replicating androids intent on their revenge. http://www.amazon.com/dp/B00EK5T6WE

Clues, and misleading facts!

The most important thing in a mystery story is that when everything is resolved, some clues as to why the protagonist sorted it out are given. The real masters (Agatha Christie comes to mind but I draw the line at mistresses!) leave some clues in the story that the reader could pick up, but usually in a way that the reader is most unlikely to pick them up. The aim should be to tidy up the story, but a further objective might be to reward the perceptive reader. Perhaps the hope is the reader will think how clever the protagonist was, but of course having the writer directing gives the protagonist something of an advantage. There are different sorts of clues, but the one I am picking on here are the lies. The point of a mystery story, of course, is that the guilty parties may always lie, and catching out the lies is part of detection, although that method is complicated by those innocent of the specific crime also lying to cover up something else. The problem comes when the author accidentally makes some just plain mistakes.

A number of stories have the elements of mystery about them, even if they are not really mysteries, and a book that led me to write this blog is Frank Luna’s Red Storm. It is nominally a SciFi thriller set on Mars, but it has the elements of a mystery embedded in it. There were a number of statements that were incorrect; some could have been intended as critical clues, and if so they were really good ones, but their value was reduced for me through the odd mistake. I mentioned this in a review, and maybe I was a little hard on Frank because the “facts” about Mars change. Maybe in another couple of decades someone will do the same for my Mars novels. In this sense, if you read Kim Stanley Robinson’s Mars books, there is quite a bit there that is almost certainly wrong, BUT these books should not be read as what Mars is like, but rather an archive of what Mars was believed in the early 1990s to be like. Since Frank’s errors were similar, perhaps he was merely out of date.

Back to the issue of clues: how do you introduce deliberate clues to identify the guilty? Here are my views. One thing that must not be done is to present it with a flag, effectively saying, “Hey reader, big clue here!” On the other hand, if it is so obscure that nobody could possibly see it, it is really a waste of time. Good clues are to test the reader, not to demonstrate some sort of superiority on the part of the author. One guideline is not to tell the clue if you can help it – try to make the guilty party say it. Failing that, get someone else to say that (s)he had heard that . .  and try to say who originated it, unless that is part of the further puzzle. Try to avoid showing lies as observations, and try not to present told descriptions that are untrue.

There is one further point. The author, particularly in scifi, may wish to introduce something that may or may not be true, but is believed by most not to be. How do you introduce that? In my Red Gold, I put forward a different theory of the origin of the Martian atmosphere. The reason was, the story is about fraud, and I needed a totally unexpected discovery to expose it. This was introduced as a discovery, and to elaborate, I put a more complete discussion as an appendix, so as to give those interested something deeper to consider (I actually believe the discovery will be made, so up to a point I have falsified my own plot!).

Anybody else have any ideas on how to do this? Finally, since I have picked on a specific author, I should add that I enjoyed the book, and if you like reading Scifi on Mars, Red Storm is well worth considering.