Astrochemistry - Science topic

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The lightest elements (mainly hydrogen and helium and in trace amounts lithium and beryllium) were formed about 100 seconds after Big Bang through the Big Bang nucleosynthesis (this process lasted up to 20 minutes after Big Bang).

After the formation of stars new elements, from helium to iron, are produced in stellar nucleosynthesis (thermonuclear fusion: CNO cycle, proton–proton chain reaction and triple-alpha process) during stellar evolution.

Elements higher than iron are produced in supernovae through the r-process and s-process.

A very good book about this and generally about properties of stellar interiors and the structure and evolution of stars is: "The Physics of Stars" A. C. Phillips.

About the nuclear physics of stars, you can see also a book of Christian Iliadis "Nuclear Physics of Stars".

Dear Sir

I think the links below will benefit you in your search

Best Regards

Thank you Debasish sir for the suggestion. I will try it.

Hi James,

In this case it's room temperature 26 °C. Would not the gas exhibit a discrete absorption spectra but the solid would exhibit a continuum of frequencies? Also if the concentration of the gas is gradually increased then wouldn't this cause the gas to gradually shift to becoming  more a continuum of frequencies but still having a central frequency that is it's discrete absorption spectra frequency. 

Thank you marcin gronowski sir. It is very helpful. 

Please check out http://iopscience.iop.org/article/10.1086/505112/fulltext/ . Nuclear reactions in the corona are observed during large flares. The reactions tend to involve heavier nuclei and are not the same as the p-p and CNO reaction chains that fuel the Sun and other stars.

I am quoting from Steven Weinberg's book the first three minutes,

The answer to your question therefore is "none of these". In the beginning there were just elementary particles and their antiparticles. But it is possible to formulate certain theories of baryogenesis. These theories explain how abundance of matter started to dominate over than of anti matter and how stable particles (which are seen today) such as the proton were formed.

thank you, Oleg B. Gadzhiev  for your valuable answer. I will read all the articles you suggest and cite them if relevant for my work specially article 2.

thank you Mr. Oleg B. Gadzhiev 

please tell me if QST2 did not provide good guess for TS what else can be use? also I am working on one reaction which I suppose could be Barrierless. How I confirm that reaction is barrierless?

First, let me stress that the activation energy is not a well defined microscopic quantity, but a convenient parameter in which we can hide our ignorance on the details of the many different possibilities for the individual reactions. 

This having been said, the importance of quantum effects at a given temperature can be assessed by comparing the corresponding thermal energy with the characteristic energies for the different statistics, that is, the zero point energy for enclosing the particle in a given volume, which, for Fermions is known as the Fermi energy and for Bosons as the condensation energy.

As an example, let us take the Fermion case. For electrons in sodium metal, with a particle density of 2.65 x 10^28 /m^3, the Fermi energy is 3.24 eV and the Fermi temperature is 37'700 K, proportional to (N/V)^(2/3) and inversely proportional to the mass of the particle. I am not an expert in solution chemistry (if the concept makes sense  at all at such low temperatures), but I think it is fair to assume that, just on steric grounds, the number density of the reacting molecules is at least two orders of magnitude smaller, which divides the sodium result by a factor of the order of 20. Then, we know that the mass of the nucleon is 1836 times larger than that of the electron, and already for a small molecule like methane, this means division by further factor, this time of the order of 30'000. So you see that the degeneracy temperature at which quantum effects become important is below 0.1 K. Exactly the same reasoning holds for the boson case.

In summary, there is no need to change anything in your treatment.

Best regards, René Monnier

Dear John,

I remember having come across reports (on sciencedaily.com) of independent studies that (1) looked for microbiota on the exterior of jet planes, and (2) smeared plasmid-bearing bacteria of known genotype on the exterior of the planes, let the planes fly, and retrieved the smear later to evaluate the survival of the bacteria. I may be wrong in technical terms, but this is probably true to the studies. Interestingly, many microbial life forms were found on the jet exterior, and also the plasmid-bearing bacteria survived long hours of high-altitude flights. These data indicate that microbial life is sustainable in conditions we usually consider inhospitable (ultra-low gravity, ultra-low pressure, acute desiccation, very low temperature, radiations...) and that can possibly migrate in the space. I shall try to retrieve the references and publish here.

Going back to the type of experiments astrobiology should be doing, here is an excellent new review towards identifying signatures of life on exoplanets:

As mentioned only motivated persons can produce and published scientific research in the academic environment. It is a hard job to produce regularly novelty, with enough contribution for the scientific community, impact in the society or industry, and present it in a way that is interesting for the other researchers and for the publishers.

In my opinion, who is really motivated by money usually stay far away of the universities as they do not pay (also cannot) the hours of work you need to achieve (and I underline again here) high levels of novelty, contribution significance and interesting work.

The universities give the scientific environment, the scientific nets, the equipments (labs), the assistants, the computers and software, libraries, inside culture and knowledge, and so on. This is very expensive to build and keeping it along generations as well as maintaining a permanent improvement, beside the serious teaching contribution for which is possible to a university to stay alive within reasonable costs.

I know very few about the universities in third world. Anyway, would recommend to check the payments (are they receiving a dignified wage, i.e. a full-time job must allow to keep a family with kids at university) , to check the number of hours of teaching duties (a very good university lesson is also a hard job, which require preparation, adaptation and a lot of energy which must be balanced between research and teaching) , to check the working conditions given at university, check if they have freedom to study the problems they want or they consider the most important (one must believe in the importance of the work being doing), check the mentioned tolerance to failures, and to check for the access given to the international scientific community as well as to the society.

Universities should invest some of their budget in inviting senior recognized scientists to stay for some periods, to evaluate the environment , transmit experience and their way of working in the field. Young talented future candidates will enrich a lot contacting recognized scientists that are interested in working with these junior fellows.

Of course, with globalization many of sharing opportunities are being closed by the extreme competition and commercialization. Many available knowledge where in the past easily passed from university to university, but not nowadays.

Also, removing responsibility of seniors on preparing future generations to replace them as a natural event when they retire is doing damage. Of course, retirement income should also be a dignified.

Finally, this express only an opinion at this moment which can be changed with discussion and reflection, but hope contribute for the discussion in this very complex subject.

Dear Colleagues,

I am forced to write repeatedly some, as I think, obvious questions that relate to the problem of living matter origination, in connection with the alternate pretensions from Dr. Kenneth Towe.

According to our Life Origination Hydrate Theory (LOH-Theory), the primery living matter originated within the methane hydrate honeycomb structure from CH4, and NO3 and PO4 ions underground or/and underseabed.

It is well-known that living organisms are really detected in great quantities underseabed up to the depth of 400m and under 400-5000-m water colomns at different regions of the ocean. Living matter was also detected deep underground in Siberia. In addition, it is known that different living organisms were observed in water in the Mariana Trench at a depth of about 10000 m. All this information is presented in our papers, where corresponding references are given. Meanwhile, Dr. Kenneth Towe writes that no underground living matter is possible. This shows that he does not read the literature on the subject discussed by him and bluffs the members of the community. Mark Tessera also writes in his issue about this.

Dr. Kenneth Towe anew put on a pedestal the Miller’s and Urey’s experiments on the amino-acid syntheses from the H2O-CH4-NH3-H2 mixtures under the electrical discharges; these experiments are based on Oparin’s hypothesis, which was first formulated in 1924. It is well-known that these experiments led to nothing but syntheses of some aminoacids, although many tens of researchers performed similar experiments in different laboratories. Meanwhile, these experiments were senseless and were condemned to failure. Why is this? The detailed answer is given in our papers, and I am forced to repeat it. (1) Oparin thought that the living matter entropy is so low that the enthalpy change is not capable of making negative the free energy change in the course of living matter syntheses from minerals and that, therefore, external energy is necessary. Oparin was mistaken; methane+niter+phosphate are capable of giving DNAs, amino-acids, and, of course, peptides with no external energy. This is proved thermodynamically and is beyond doubt.

Dr. Kenneth Towe does not understand that not amino-acids but DNAs represent the ground of living matter and that just their formation determines origination of life. Amino-acids originate and are being produced in the course of living matter origination and in the course of metabolism as the side products and from those source substances from which DNAs form. However, DNAs are capable of forming within a natural mineral matrix only and the same matrix forms the cellular protoplasm, and, thus, the process of living matter formation is governed by the process of formation/destruction of the gas-hydrate structure. This matrix is exactly appropriates by the sizes of its cavities to the DNA components and to the DNA as a whole. The occurrence of the matrix gives explanations for the structure and composition of DNAs and for the phenomenon of monochirality. Unfortunately, the same I should say to Marc Tessera as well. All the mechanisms of living matter origination and development are described in our papers, and these mechanisms are necessary and sufficient for life origination and development. Each step of these processes is detailed in our papers; numerous thermodynamic calculations confirm them.

In addition, it is necessary to understand that neither single nor rare events of DNA origination couldn’t become the source of life as of natural phenomenon. In order that the phenomenon of life would appear, origination of a multitude of DNAs in close proximity to each other is necessary. Only such an event could be conducive to development of life as phenomenon and to symbiotic interactions of primary DNAs.

The LOH-Theory allows for answering the following questions. (1) In what phase did the LMSEs form? (2) From what substances did the LMSEs form? (3) By what mechanism did the N-bases, riboses, and nucleosides form? (4) Is Nature capable of synthesizing LMSEs from minerals with no external energy? (5) How had methane hydrate originated? (6) How had CH4 and NO3– met together? (7) Why no substance but NO3– reacted with CH4-hydrate? (8) How did DNA- and RNA-like molecules form from nucleosides? (9) Is there a relation between DNA and RNA formation, on the one hand, and the atmosphere composition, on the other hand? (10) Why do only five chemical elements usually enter the DNA and RNA composition? (11) Why are N-bases entering DNA and RNA similar in their composition and structure? (12) Why are N-bases and riboses limited in size? (13) Why are N-bases not identical? (14) Why do only five N-bases usually enter the DNA and RNA composition and why do other N-bases, such as xanthine, sometimes enter the DNA and RNA compositions? (15) Could D-ribose (DR), desoxy-D-ribose (DDR), thymine and uracil exist simultaneously in a reaction mixture containing CH4 and niter? (16) How had it happened that the sequences of N-bases in DNA and RNA molecules are not random? (17) Why did Nature choose DR and DDR, but not their L-enantiomers or mixtures of enantiomers for DNA and RNA syntheses? (18) How did protocells originate? (19) What is the cause of the explosive appearance and development of living matter late in the cold periods of the Earth’s history? (20) Does living matter exist on other planets? (21) What is the cause of exclusive powerful events at the Sun, and what are their consequences for the Earth? (22) What powerful events at the Sun are expectable?

Of course, it is senseless to propose our paper for reading to the persons like Dr Kenneth Towe who knows in advance how living matter originated and develops. I propose to do this to the researches free of dogmatism and capable of logical thinking and analyzing different sides of these phenomena.

I can’t discuss with Dr. Kenneth Towe personally because he is a rude fellow. Earlier, he was very rude to me, then he begged my pardon (I saved these files); however, two-three days ago, he corresponded with my colleague Elena Kadyshevich in improper form again. Meanwhile, if any idea is not liked by a researcher it doesn’t mean that this researcher should be rude to its author. In addition, he expresses himself in contemptuous form about papers that he refuses to read. Mark Tessera and Elena Kadyshevich also noticed this feature of him.

I totally agree with Charles Francis. The composition of the galaxies will depend on the generation of the galaxies as well as the constituent stars in the galaxy. If a galaxy contains huge numbers of high mass stars, then the probability of Supernova explosions in the galaxy will go up, thus filling the galaxy with higher mass elements. Also galaxy mergers may occur and this can also alter the composition of the new galaxy formed as compared to the parent galaxies.

The Earth's atmosphere is largely a biological construct; Venus's isn't.

First, notice that, although Venus has Nitrogen and Argon as apparently minor constituents, the partial pressure of Nitrogen in the Venus atmosphere is 3.2 bars, actually more than the Earth's 0.78 bars, and the Argon partial pressures are very close, 0.009 and 0.006 bars. (The total mass of Venus and the Earth are close enough that you can regard the partial pressure as a proxy for the total mass in comparing the two atmospheres.)

The real difference is in the location of the Carbon. The Earth has 3.5 x 10^-4 bars of CO2 in the atmosphere, while Venus has 89 bars of CO2. However, it turns out that both planets have about the same amount of crustal carbon, but the Earth has most of its carbon in the ground, and some in the oceans and the biosphere. If you convert mass to partial pressure, we have the equivalent of 0.02 bars of CO2 in the oceans, 0.001 bars in the biosphere, and at least 29 bars in crustal rocks. If you could somehow heat the Earth's surface to 470 C, all of that carbon would be driven into the atmosphere as CO2, and the Earth would have an atmosphere a lot like Venus.

The real major difference (in terms of total mass) between the surface regions of Earth and Venus is in the presence or absence of water. The Earth has a lot of water, enough to cover the surface to several km depth if the surface was a perfectly smooth sphere, while Venus has very, very little (enough to cover a smooth surface to a depth of maybe 2 cm). Unless there is some unknown means of sequestering hydrogen in the hot crust of Venus, almost all of its hydrogen has presumably been lost to space. As it happens, models show that the Earth has a "cold trap," that keeps water out of our stratosphere (where solar UV would disassociate it and create free Hydrogen which could be lost to space), while Venus does not, so the current thinking is that this fairly slight difference in atmospheric dynamics is sufficient to dessicate Venus, leaving it in the dry state it is today. There has been a lot of recent debate as to how cold traps affect the "habitable zone" of exoplanets, and the real question is, how do you keep a hot planet from drying out. (I have a feeling there is a biological connection here as well, but that is just my intuition.)

Mars is a different case, which I'll cover in a separate post (unless someone beats me to it).

I believe such spectra are available in the ISO archive : http://iso.esac.esa.int/ida/

These nebulae have been observed with the SWS instrument.

Best regards, Olivier

Isotopic anomalies in solar system objects can be due to 1) nucleosynthetic effects, i.e., material that has been synthesized in other stars and preserved in presolar stardust grains, 2) molecular cloud fractionation effects at very low temperatures that have been preserved in very primitive organic matter as H-C-N anomalies, 3) anomalies in short-lived radionuclides like 26Al that are due to their different decay at different times after solar system formation, 4) cosmogenic effects due to exposure to the galactic high energy environment (e.g., spallation reactions), 5) Anomalies in oxygen isotopes that are due to CO self shielding under UV irradiation of the young Sun (mass-independent fractionation), and 6) mass dependent fractionation. The question is to what composition you want to refer your anomalies. For instance, the Earth and most meteoritic materials are isotopically anomalous in N and O with respect to the Sun (see results by the GENESIS mission)!

Are the conditions on Mars such that they seem to preclude life or is it more that we have not found evidence of life on Mars?

(I wrote an answer this morning, but it seems to got lost in cyberspace; in hindsight I think that I did not answer the question correctly, so I try again).

My answer:

In the absence of a model for the origin of life on earth we cannot prepare tests for whether life is possible on a specific extraterrestrial site (I prefer not to use the word planet, as extraterrestrial dust, comets, meteorites, moons, Kuiper Belt Objects, planetary nebulae and even the atmospheres of cold stars should be considered as potential habitats as well).

We can only check whether life as we know it on Earth could live at a certain site; this already yields an immense variety, as life seems to be present almost everywhere on Earth: from deep down in sediments to high up in the atmosphere. Terrestrial ecology therefore yields many possible shapes of life. But is this set comprehensive?

Schulze-Makuch's book described several shapes that extraterrestial life could take. But again, this set is possibly not comprehensive.

We do not how life on Earth emerged, i.e., the first stages that life on Earth assumed are unknown. Those first stages may be difficult to recognize, as we do not know how they looked like. The eyes can only see what is already in the mind.

Obviously finding out how life on Earth emerged would help. I myself have come up with a model for the origin of life in which the first organisms were essentially heat engines. Such organisms could live on thermal cycling (as in a convection current) or on a thermal gradient; they would NOT need sunlight. My papers state that such conditions are present in many extraterrestrial places (for instance: organisms living in the dark on convection underneath surface ice).

To get back to the stated question. If one could demonstrate that life on Earth could live on thermal cycling or in a thermal gradient, one would have done a convincing test that extraterretrial life is possible almost everywhere. Candidates abound for such life: they range from microorganisms growing in tap water to the jelly fish clogging up the cooling water inlets of Swedish nuclear reactors that are in the news today.

I didn't read this book, but I know well the present hypotheses that relate to this problem. All they are based on Eddington's 100-year-old ideas. According to these ideas, just the fusion reactions are the cause of element formation. For 100 years, no proofs for this assumption are obtained; the neutrinos that are used for this aim can be explained by the beta-decays in the near-solar space. The development of the Eddington's ideas led to a number of paradoxes and leaves today a number of unanswered astronomical and astrophysical questions. I address all researchers to our papers available at the ResearchGate (Elena A. Kadyshevich, Victor E. Ostrovskii, «Development of the PFO-CFO Hypothesis of Solar System Formation: Why do the celestial objects have different isotopic ratios for some chemcal elements?», Adv. in Plasma Astrophys., Proc. IAU Symp. 274, 2010, 95-102; «PFO-CFO Hypothesis of Solar System Formation: the presolar star as the only source of chemical elements for the Solar System»; EPSC Abstracts, v. 8, EPSC2013-38 2013; V.E. Ostrovskii, E.A. Kadyshevich, «PFO-CFO Hypothesis of Solar System Formation: the notion on the Sun-like stars and their transformations», EPSC Abstracts,v.8, EPSC2013-145, 2013 and to other papers of these authors). These papers are based on the principally new approaches to understanding of the problem of the Solar System origination and they give, in particular, a new explanation of the problem of formation of chemical elements. According to this explanation, the entire Solar System and all its chemical elements were formed by a unique mechanism on the basis of the presolar star. Our approach allows explanation of a number of paradoxes and gives answers to a number of questions. It contradicts to no observations and events.

In principal solid-state NMR can be run on condensed phase samples like powders, gels , and colloids. However, as Hiram and Craig suggest you will have at least three problems.

1. You will need to spin the sample to get a high-resolution spectrum. This will be difficult to do without melting your sample to get it into the rotor.

2. You will need to look at protons, which is difficult to do because of the strong dipolar coupling between protons.

3. You will have to irridate it somehow which is only available on specialized spectrometers