2069 planeta Tierra (Spanish Edition)

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I arrived at this story by reading The Library at Night by the historian Alberto Manguel, which gives an overview of the great libraries across history. The book made a brief note that in the extermination camps of Auschwitz, eight old books were collected into what may be the most minuscule and clandestine public library in history. When I closed the book, this question kept knocking on the door of my curiosity: How was it possible to have a library in the hell of Auschwitz?

And then I started looking, and found more than I ever imagined. The SS wanted a barracks to keep the children entertained while their parents worked like slaves in the workshops of the camps. They put a German Jew named Fredy Hirsh in charge of organizing songs and games, but they wanted nothing of religion or teaching.

The greatness of Hirsch is that, in a place where life hung from a thread and anyone could be sent at any time to the gas chambers, he put a couple of boys at the door as guards, while inside he organized a school. He even managed to gather eight old books clandestinely. To me, what he did seemed like something far more important than heroism: How did you learn about Dita? And how did you first get in touch? Then finally, I found a web page where someone had it for sale, and I wrote to an email address to make a request for the book. So I asked her if she had anything to do with the girl from Auschwitz.

From there, we began a correspondence by email, and finally found ourselves together in Prague. Knowing Dita Kraus is one of the important things that has happened in my life. I never considered the age of the reader, really. In fact, I thought the subject could turn away some young readers looking for entertainment in a book. My surprise has been that, since the first edition in Spain, I began receiving messages of appreciation from young readers—by the way, mostly girls—because they identified so strongly with the story.

How has the reception of your novel been in Spain, and in other countries where it is published? And what is your hope for it in the United States? This is my first book published in the United States, and I have no idea what the reception will be like. In Spain the book has had a very good reception. There must be more than a dozen editions by now. For example, in Italy the novel has gone quite unnoticed, but in the Netherlands I have already lost count of the number of editions and it continues to be reissued.

Even in Japan, this summer readers voted it as their favorite translated book of the year. This shows that although our planet is enormous, we are all closer than we realize. What does Dita think of all this? Amparad a la viuda. Arcana Coelestia , , , , , , Apocalypse Revealed 47 , , , , , , Conjugial Love 12 , Apocalypse Explained 67 , , , , , , On the Athanasian Creed 30 Charity 12 , 26 , Marriage 51 , 93 , 95 Scriptural Confirmations 4 , 13 , 39 , 82 Sujets spirituels: Scots Gaelic Gospel of Mark. Seall chaidh fear-cuir a mach a chur.

Esan aig a bheil cluasan gu cluinntinn, cluinneadh e. Thugadh dhuibhse eolas air run -diomhair rioghachd Dhe: Nach tuig sibh an dubhfhacal so? An toirear coinneal, gus a cur fo shaghach, no fo leabaidh? Thugaibh an aire dhan rud a chluinneas sibh. Leis an tomhas leis na thomhais sibh, toimhsear dhuibh air ais, agus cuirear tuilleadh ris dhuibh. Mar so tha rioghachd Dhe mar gun tilgeadh duine siol anns an talamh,. Co ris a shamhlaicheas sinn rioghachd Dhe?

Rachamaid null thun an taoibh eile. A Mhaighistir, nach eil umhail agad gu bheil sinn a dol a dhith? Gabh fois, bi samhach. Is laidh a ghaoth; agus thainig fiath mor. Carson a tha eagal oirbh? Nach eil creideamh agaibh fhathast? Agus ghabh iad eagal mor; is thuirt iad ri cheile: Commentaire sur le chapitre Histoires: Arcana Coelestia 29 , , , , , , Apocalypse Revealed 87 , , , , , , Apocalypse Explained , , , , , , Marriage Scriptural Confirmations 14 , 87 Etudes bibliques: Arcana Coelestia Elliott translation.

As this has reference to the Lord's Divine Rational as regards truth, the expression 'fearing God' is used here, not 'fearing Jehovah', for when truth is the subject the name God occurs, but when good is, the name Jehovah occurs, Arcana Coelestia , , What is meant in the Word by 'fearing God' becomes clear from very many places there when these are understood as to the internal sense. In the Word the fear of God means worship, and indeed worship based either on fear, or on good that flows from faith, or on good that flows from love. Worship based on fear is meant when those who are not regenerate are the subject, worship based on good flowing from faith when regenerate spiritual people are the subject, and worship based on good flowing from love when regenerate celestial people are the subject.

This is evident in the Book of Kings, The children of Israel feared other gods and walked in the statutes of the nations. The nations brought into Samaria did not at the beginning fear Jehovah; therefore Jehovah sent lions among them.

Then came one of the priests whom they had made captives in Samaria, and he dwelt in Bethel and was teaching them how to fear Jehovah. Jehovah had made a covenant with the children of Israel and had commanded them, You shall not fear other gods, nor bow yourselves down to them, and you shall not serve them, nor sacrifice to them, but you shall fear Jehovah, and bow yourselves down to Him, and sacrifice to Him.

Here 'fearing' clearly stands for worshipping. In Isaiah, Because this people have drawn near with their mouth, and honoured Me with their lips, but their heart has been far from Me, and their fear of Me has been a commandment of men that has been taught to them Here 'their fear of Me' stands for worship in general, for it is said that that fear was 'a commandment of men'. Palaeogeography, Palaeoclimatology and Palaeoecology, , Philosophycal Transactions of the Royal Society of London, , Journal of Phycology, 23, Kluwer Academic Publishers, Amsterdam, Junio 16, Manuscrito corregido recibido: Enero 6, Manuscrito aceptado: Growth of Bacillus pumilus and Halomonas halodurans in sulfates: The objective was to demonstrate whether these cultures have the ability to grow, not only in media enriched with sodium chloride, but also with other salts of astrobiological interest.

The importance of this monitoring was to evaluate the fitness of these strains to the hypothetical salt content and composition of extraterrestrial sites, such as the ocean of Europa, one of the satellites of Jupiter.

The mechanism of fitness used by these bacteria was investigated by characterizing the compatible solutes accumulated by each strain. Bacillus pumilus was cultivated at 0. Bacillus pumilus se hizo crecer en medios modificados con 0. The search for life beyond Earth is focused on the finding of liquid water as the main factor that qualifies a habitable planet or satellite.

In this sense, the discovery of geological evidence pointing to the possibility of water running on ancient Mars Squyres et al. One of the most significant results of the Galileo orbiter mission was the discovery of geological features on the surface of Europa Pappalardo et al. These observations were supported by magnetometer studies Khurana et al. While sodium chloride NaCl and other chlorides are common in bodies of water on Earth, the spectral evidence shows that sulfates either of magnesium or sodium MgSO 4 or Na 2 SO 4 are present on the deep ocean of Europa.

The reason can be found after an examination of the material that formed each of these planetary bodies. The organisms capable of surviving at high levels of salinity could be halotolerant or halophilic. As the average salt content on terrestrial oceans is around 3. However, the stress imposed by salts different from sodium chloride is not necessarily the same. The adaptive strategies for tolerance at high MgSO 4 concentrations were not explored, but the authors noticed some unexplained differences in the growth rate and stationary-phase maximum densities when their isolates were exposed to different sulfate salts.

There are some reports about the substitution of NaCl with other salts Oren et al. These molecules are known as compatible solutes as they do not interfere with the metabolism of the organism that incorporates them. Compatible solutes aid in the stabilization of some enzymes, the maintenance of cell volume and in providing protection from extreme parameters, such as high salinity, high or low temperature, or desiccation.

In this paper, we present data on two microorganisms growing under different salt conditions. Basal media were supplemented with the corresponding molar concentration of the salts under study NaCl, MgCl 2 , Na 2 SO 4 or MgSO 4 to achieve a particular water activity value a w as shown in Table 1. The culture media were inoculated to have an initial optical density of 0. Bacterial growth was monitored as changes in the OD at regular time intervals using a microplate reader Stat Fax until the stationary phase was reached.

All incubations and measurements were done by triplicate. Betaine and ectoine standards, as well as deuterium oxide Liquid cultures of B. Cultures without NaCl were used as controls. The compatible solute extraction process was based on the work reported by Roberts Cultures of one-liter were grown until the exponential phase was reached. This means an OD value of 0. The biomass was separated from the liquid medium by centrifugation at xg for 20 min.

The sediment was washed twice with a NaCl isotonic solution. The sample was dissolved in NaCl isotonic solution and centrifuged again for 15 min. After this time, it was centrifuged for 30 min at xg. The ethanolic supernatant was separated and the ethanol was evaporated using a vacuum chamber. The residue was suspended in 0. Resultant spectra are identified as the sample spectra. On the other hand, the spectra of betaine and ectoine were obtained from solutions prepared in D 2 O.

These were labeled as the standard spectra. The identification of the compatible solutes accumulated by the bacteria was performed by comparing the chemical shift of the signals present on each of the standard spectrum with those present on the sample spectra. Bacillus pumilus grows optimally in nutritive medium depleted of salts where the water activity a w is 1. This response has not been reported before probably because halotolerant and halophilic strains are firstly described in terms of their NaCl tolerance.

Only when a w values are higher than 0. On the other hand, when the culture media was added with MgCl 2 , the grow rates drastically decrease until the value of 0. These results are noteworthy in different ways. First, it is notable that B. Then, this strain apparently prefers the culture media enriched with Na 2 SO 4 above any other of the tested salts, particularly MgCl 2.

The highest salt concentrations endured by B. The case for Halomonas halodurans , a moderate halophilic bacterium, is quite different. This strain was also able to grow in all the essayed salts, and again, it seems that the growth rates in Na 2 SO 4 are higher when compared with NaCl, MgCl 2 and MgSO 4 within the interval of a w values tested. This is particularly true for a w values below 0.

There appears to be salt concentrations that display an optimal growth rate, 0. The highest salt concentrations endured by H. Changes in turbidity were measured at nm. Data points are mean values of three replicates. The NMR spectra corresponding to betaine and ectoine, used as reference materials for the compatible solutes, are shown in Figure 2. The chemical shift, expressed in parts per million ppm , and the multiplicity of each signal were used as the identification parameters. This information is detailed in Tables 3a and 3b. The NMR spectrum of B.

The 1 H spectrum shows some signals between 1. However, none of them displayed the specific chemical shift of the signals observed on the betaine and the ectoine spectra Tables 3a and 3b.

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It can be concluded that there is no presence of any of these compatible solutes in this B. Likewise, the 13 C spectrum showed no signals in the range used by the reference materials. The situation is of course different in the cultures modified with NaCl. The 1 H NMR spectrum obtained at a concentration of 0. Some other small signals were visible, but due to their low intensity, were difficult to assign.

Betaine was also evident in the 13 C NMR spectrum, where its three strong signals were visible and could be corroborated likewise with the reference spectrum Table 3a, and Figure 3. When the NaCl concentration was increased to 0. This was a favorable situation for the identification of the solutes. A broad comparison was done, based on the integrated area of the main signal for each identified compatible solute. Thus, it was possible to advance differences in the type of compatible solute accumulated by each bacterium as a function of the concentration of NaCl Table 4. Additional signals were also present on the 13 C NMR spectra and were assigned on the basis of the chemical shifts reported by Roberts who presented the spectroscopic parameters of some of the most common compatible solutes accumulated by halotolerant and halophilic organisms.

In this sense, we find chemical shifts that could be assigned to glutamate. However, these identifications need to be taken cautiously because they must be confirmed through the acquisition and comparison of the spectra of a glutamate standard. Nevertheless, the approach used here can help in the recognition of the compatible solutes used by B. Chemical shifts ppm and multiplicities of the structural fragments identified in the 1 H and 13 C NMR spectra corresponding to the compatible solutes present in extracts of Bacillus pumilus H3 grown at different NaCl concentrations.

Chemical shifts ppm and multiplicities of the structural fragments identified in the 1 H and 13 C NMR spectra corresponding to the compatible solutes present in extracts of Halomonas halodurans grown at different NaCl concentrations. Compatible solutes accumulated by Bacillus pumilus H3 and Halomonas halodurans at different NaCl concentrations.

The identification of the compatible solutes in the extracts from H. Luckily, some of them could be assigned to the presence of betaine and glutamate, as was shown when compared with the reference spectra and the spectroscopic parameters reported by Roberts as previously explained. These results are shown in Figure 4. The comparison of the compatible solutes accumulated as a function of NaCl concentration is shown on Table 4.

As far as we know, there is no previous identification of compatible solutes accumulated or synthesized by Bacillus pumilus or by Halomonas halodurans in NaCl. Different reports corresponding to organisms phylogenetically related have been identified. For example, Kuhlmann and Bremer mentioned that the Bacillus genus, without specifying which species, principally synthesize de novo glutamate, ectoine and proline. We found glutamate in our experiments. When the salt concentration is increased, betaine seemed to be preferably accumulated.

Our results showed that H. Unfortunately, these authors did not report any qualitative or quantitative estimation. It should be noted that the presence of glutamate requires confirmation by acquiring its standard spectra as previously mentioned. Nuclear magnetic resonance spectra of a betaine, b ectoine and c a B. Nuclear magnetic resonance spectra obtained from a B.

Signals corresponding to the chemical shifts of betaine red circles , and glutamate blue diamonds are identified. Nuclear magnetic resonance spectra obtained from a H. The search for life in the solar system centers on the search for liquid water mainly due to the fact that life on Earth is defined by three basic requirements: An extensive number of studies, related to the environment of Europa, has pointed to this satellite as a world with the highest potential as a modern habitat for microbial life Pappalardo et al.

The temperature of the water in this ocean can be on the order of K, not far from the limit of biological activity on Earth Neidhardt et al. Due to the composition of the primordial material proposed for the satellite, sulfur chemistry is important Priscu and Hand, as the ocean is probably enriched with sulfates. Dissolved salts prevent the freezing of the ocean on Europa. Despite the Europan ocean's depth, which could be about km, the pressure in its bottom is not that great because the gravitational acceleration is less than one-seventh of the acceleration on Earth Priscu and Hand, It is most likely that if life exists or existed on Europa it would be from the halotolerant, psychrophilic, or barophilic type, or a combination of them i.

Here, we have demonstrated that the mesophilic bacterium Bacillus pumilus can adapt to saline stress through strategies such as compatible solute accumulation when its media is modified with NaCl. Moreover, this bacterium can be considered a halotolerant species due to the fact that it was able to grow on NaCl concentrations higher than those found as average on terrestrial water bodies. Further studies are needed, in order to determine if a similar strategy, of accumulating compatible solutes, is used when this halophile has to deal with these chemically different salts.

There are no specific values for the salinity on the ocean of Europa. However, empirical constraints have been proposed on the basis of the Galileo data that allow values from 1. Extrapolating the salt concentration used in our experiments we have covered an interval of 2. This implies that Bacillus pumilus and Halomonas halodurans are perfectly capable of surviving in the actual Europan ocean, if just the salinity value is considered.

Of course, we have to keep in mind that other constraints should be considered including temperature, pH of the ocean, availability of oxygen, or radiation Marion et al. The availability of free-energy is also a critical aspect. In this regard, it has been proposed that metabolisms such as sulfate-reduction, iron reduction, methanogenesis and others that are active in anoxic environments on Earth, might exist on Europa Gaidos et al. We have demonstrated that Bacillus pumilus , a non halophilic bacterium, and Halomonas halodurans , a moderate halophilic bacterium, were able to adapt to culture media modified with different concentrations of NaCl, MgCl 2 , Na 2 SO 4 and MgSO 4 within an interval of water activity a w between 1.

Information about the strategy used by these bacteria to cope with the stress imposed by the different levels of salinity was inferred by the identification of some compatible solutes by NMR. The adaptive strategies used by microorganisms on Earth reveal that most of the physiological stress can be overcome as long as the environment contains liquid water Ball, Detailed studies to define the survival of halophilic bacteria at higher salinity concentrations, as well as the identifications and quantitative estimations on the chemical nature of compatible solutes accumulated on the presence of salts different to NaCl are needed.

A mission devoted to perform a detailed analysis of the surface and ocean of Europa to determine the concentration of the salts dissolved in the ocean, and to determine if there are energy sources available for the development of any of the metabolisms known for terrestrial organisms is also needed.

Journal of Bacteriology, , Applied and Environmental Microbiology, 68, Evaluation of the geological evidence: Journal of Geophysical Research, , Saline Systems, 1, Methods in Microbiology, 35, Archives of Microbiology, , Saline Systems, 4, Origins of Life and Evolution of Biospheres, 39, May 5, Corrected manuscript received: January 30, Manuscript accepted: This paper reviews the distribution of methane CH 4 in our Solar System, as well as its sources and sinks in the atmospheres of the main Solar System bodies.

Methane is widely distributed in the Solar System. In general, the inner planets are methane-poor, being Earth a unique exception, whereas the outer planets have CH 4 -rich atmospheres. In general, the atmospheric chemistry of this compound is dominated by the solar radiation although in O 2 -rich atmospheres this compound participates in a reaction system that removes atmospheric CH 4. In our planet most of the atmospheric CH 4 is produced by lifeforms, reason why scientists have proposed that the simultaneous detection of methane signal along with oxygen O 2 or ozone O 3 signals in the atmospheric spectra of planets may be good evidence of life.

Therefore, the study of this gas at planetary level is important for understanding the chemical reactions that control its abundance on the exoplanetary atmospheres and to classify possible inhabited planets. The Solar System was formed by the gravitational collapse of a primordial gas nebula. The center of this nebula collapsed faster than its outer edge, forming the Sun at the center and a protoplanetary disc around, latter processes formed planets from the dust Cloutier, The temperature in the inner protoplanetary disc near the Sun was high enough to evaporate volatiles like methane, which is decomposed by photolysis and it is dragged later by the solar wind.

In the outer regions of the protoplanetary disc, the low temperatures allowed that ices and volatiles could be preserved. Methane is preserved in ices called clathrates, these solids present structures that can capture methane in their interior. Here, we review the CH 4 abundances in planets and small bodies of the Solar System.

Inner planets are the four closest planets to the Sun: Mercury, Venus, Earth, and Mars. They are small planets composed of silicates and iron. Volatiles in inner planet atmospheres as Mercury, Venus, Earth and Mars, are mainly the result of degassing from their interiors Cloutier, These deposits are located in permanently shadowed zones of the north polar region where the regolith has temperatures similar to those of the icy Galilean satellites, allowing the cold-trapping of materials from comets and rich-volatile meteorites Neumann et al. Methane is present in comets but thermal stability models do not predict its presence in cold-traps due to its higher volatility compared to water Zhang and Paige, These chemical species would be outgassed and then cold-trapped in colder regions of the planet.

Until now, no detection of methane has been reported for this planet. A plausible explanation is that the CH 4 was the result of the reaction between some highly deuterated molecules in Venus atmosphere and terrestrial CH 4 that contaminated the instruments Donahue and Hodges, Based on the detection of NH 3 , HCl, and H 2 O in the Venus atmosphere, along with the fact that there is a strong possibility of electrical discharge in the atmosphere as a result of thermal convective turbulence, Otroshchenko and Surkov proposed that organic compounds could be formed in the atmosphere.

Their hypothesis was experimentally tested, finding CH 4 and other low-mass molecules. The studies of Otroshchenko and Surkov show that presence of organic compounds in the Venus atmosphere is a strong possibility. CH 4 levels in the atmosphere are currently around 1.

CH 4 is homogeneously mixed in the troposphere while in the upper atmosphere the highest concentrations are at the Ecuador http: CH 4 levels have changed over the history of the Earth, before the emergence of life, CH 4 sources were geological. The emergence of life increased the levels of CH 4 in an atmosphere without free oxygen, where CH 4 could have lifetimes of — years and reach concentrations of ppmv Kasting and Siefert, Then, when oxygenic photosynthesis increased O 2 levels in the atmosphere, CH 4 decreased because of a set of reactions that will be described at the end of this section.

The pristine ice cores store a record of CH 4 concentrations of thousands of years. Analysis of these cores show that CH 4 abundances ranged from 0. CH 4 has increased its atmospheric concentration since pre-industrial time to be relatively constant around 1. Recently, CH 4 is calling the attention of scientists studying climate change due to its capability as greenhouse gas. It is estimated that all CH 4 sources produce Tg yr -1 , approximately. There are no chemical reactions forming CH 4 in atmospheres such as Earth Levine et al.

Here, almost all CH 4 is produced by methanogen microorganisms. Methanogens can form CH 4 by two ways: Table 1 summarizes the CH 4 sources. The major biological sources of methane are wetlands, followed by digestion of animals such as ruminants and decomposition of biomass. An important source, linked to human activity, is the production of energy.

Other minor sources are the animal activity such as arthropods and decomposition of sediments and bacterial activity in marine environments. Serpentinization takes place in hydrothermal systems similar to the Lost City, located in the middle of Atlantic Ocean. In these sites, it is commonly said that CH 4 is formed by serpentinization but in fact, CH 4 is byproduct of a Fischer—Tropsch type reaction after to serpentinization process. The H 2 used in the Fischer—Tropsch reaction is a product of serpentinization. In contrast to the numerous CH 4 sources, there are only three sinks. Table 2 summarizes the sinks of CH 4.

OH radical rapidly reacts with CH 4 removing it from the atmosphere:. Where hv is the energy of a photon with frequency v and h is the Panck constant. The remaining CH 4 is removed trough soil oxidation, and transport to the stratosphere Wuebbless and Hayhoe, ; Houweling et al.

After being produced, either by biological activity or serpentinization, methane may be stored in clathrates. Gas hydrates belong to a general class of inclusion compounds commonly known as clathrates. Clathrates owe their existence to the ability of H 2 O molecules to assemble via hydrogen bonding and form polyhedral cavities.

Molecules like methane or carbon dioxide are of an appropriate size such that they fit within cavities formed by the host material e. Methane hydrates are particularly important Mahajan et al. Within clathrates there are no chemical bond involved between the water molecules and the gas molecules other than Van der Waals forces, but the presence of guest molecules inside the ice crystals makes the structure more stable. There are two different reservoirs for clathrates. They can be found both within and under permafrost in arctic regions and also within a few hundred meters of the seafloor on continental slopes and in deep seas and lakes Hester and Brewer, Permafrost is the largest CH 4 reservoir in Earth.

Permafrost acts as an impermeable lid, preventing CH 4 escape through the seabed. Moreover, sub-sea permafrost is potentially more vulnerable to thawing than terrestrial permafrost. A consequence of climate warming is the partial thawing and failure of sub-sea permafrost and thus an increased permeability for gases. This amount is of the same magnitude as existing estimates of total methane emissions from the entire world ocean e.

In the unlikely event that 0. CH 4 sources on Earth. CH 4 sinks on Earth. Sinks reported by a Houweling et al. Sources reported by a Houweling et al. Mars is an especial case. Thermodynamic calculations predict CH 4 should not exist in its atmosphere Levine et al. The authors estimated 0. Later, in , two groups Krasnopolsky et al. In , Fonti and Marzo made distribution map of methane on the Martian surface.

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They identify three localized sources on the Martian surface, related to probable underground water reservoirs. Their analyses suggest that CH 4 abundances vary throughout seasonal cycles. There are some hypotheses about the sources and sinks of CH 4 in Mars. For example, Krasnopolsky et al. Bar-Nun and Dimitrov proposed that photolysis of H 2 O in the presence of CO can generate CH 4 , however Krasnopolsky argues that it is not possible due to the kinetic chemistry of Mars.

Serpentinization has also been proposed e. Oze and Sharma, ; Lyons et al. The origin of CH 4 on Mars is still not clear, some authors have proposed biogenic sources such as methanogenesis via metabolic pathways e. CH 4 lifetime is years and methane should be uniformly mixed in the atmosphere. Heterogeneous loss of atmospheric methane is probably negligible, while the sink of CH 4 during its diffusion through the regolith may be significant. There are no processes of CH 4 formation in the atmosphere, so the photochemical loss must therefore be balanced by its sources Krasnopolsky et al.

It was thought that the main sink of CH 4 was its direct photolysis around 80 km from the surface. Therefore, this reaction is negligible versus its direct photolysis Krasnopolsky et al.

Their composition and chemistry are relatively similar in those planets. Jupiter is the largest planet in the Solar System with M. Methane is the most abundant species in the upper Jovian troposphere after hydrogen and helium, accounting for approximately 0. Higher hydrocarbons are produced from methane by photochemical processes in the upper atmosphere of Jupiter Taylor et al. Photolysis of CH 4 is the only sink Moses et al. Saturn is the second largest planet in our solar system. Observations from the Cassini spacecraft suggest mole fractions of CH 4 of 4. The chemistry of CH 4 in Saturn is similar to Jupiter.

The only known photochemically active volatile in the atmosphere of Uranus is methane. From observations of the Ultraviolet Spectrometer in the Voyager spacecraft, the calculated abundance for CH 4 is 10 -4 near 0. Other species normally present in the atmospheres of Jupiter and Saturn are not likely to be gaseous in the photolytic regime of the upper troposphere and stratosphere of Uranus due to the low tropopause temperature Atreya et al.

The stratospheric CH 4 is photolyzed forming acetylene, methyl-acetylene, ethane, and ethylene Orton et al.

However, CH 4 photolysis is relatively inefficient on Uranus. At lower pressures, methane is not homogenously distributed at all latitudes. This is consistent with the hypothesis that CH 4 leaking through the warm south polar tropopause 62 — 66 K is globally redistributed by stratospheric motion Fletcher et al. Their images show that Neptune contains clouds of methane ice Smith et al. Similar to Uranus, CH 4 is photolyzed in the stratosphere, producing hydrocarbons like acetylene and ethane Romani and Atreya, ; Romani et al. Later, Young et al. From these observations, the calculated methane-mixing ratio is 0.

Because Pluto has not yet been observed with any spacecraft, all its parameters have been inferred using instruments on the ground. In , the mission New Horizons will be able to characterize the surface and atmosphere of Pluto and its satellite, Charon. Similar to Pluto, its atmosphere is the result of the sublimation of the more volatile ices on its surface. The surface of Triton contains approximately 0. Titan is the largest moon of Saturn. Its bulk composition has nearly equal mass fractions of silicates and ices Grasset et al.

Methane was likely to be present in the materials that built Titan and is possible that cometary impacts were a significant source in the far past e. Present abundances of CH 4 have not been possible to explain, because it is photochemically active in the atmosphere and requires a constant replenishment over geologic time scales Davies et al. Liquid filled basins in the polar regions of Titan Stofan et al. In , the Huygens spacecraft descended to the surface of Titan measuring in situ the CH 4 mole fraction when it descended.

Huygens found that the CH 4 mole fraction is relatively constant in the stratosphere; it increases between 32 and 8 km, and remains constant near the surface Atreya et al. Titan has pressures and temperatures near to the methane triple-point, for this reason the CH 4 can evaporate from the surface to atmosphere, where it can condense and rain, forming a CH 4 cycle similar to water on Earth Roe, ; Lunine, There are not reactions to generate CH 4 in the Titan's atmosphere, so it is proposed that CH 4 may come from clathrates formed in the subnebula that originated the satellite Mousis et al.

Other authors proposed the activity of bacteria as a likely CH 4 source e. Another possibility is the serpentinization Niemann et al. These icy bodies have been studied with flyby missions and ground infrared and radio observations. Methane is a primary volatile in comets, this means that it is stored as ice in the cometary nucleus and released as gas into the coma.

The study of methane is relevant to understand the process of synthesis and distribution of organic molecules during the formation of the Solar System. On potentially habitable planets around other stars its presence maybe the result of geological or biological activity. The bodies of our Solar System, especially Earth, serve as benchmarks for understanding the origin, sources and reservoirs of this compound to identify possible inhabitable worlds around other stars. Astronomy and Astrophysics, , — Planetary and Space Science, 54, — Implications of New Laboratory H 2 quadrupole line parameters: A product of H 2 O photolysis in the presence of CO: Journal of Geophysical Research, 96, — Energy and Environmental Science, 4, — Earth and Planetary Science Letters , — P, , Microbial life in Martian ice: A biotic origin of methane on Mars?: Planetary and Space Science, 58, — Surface volatile transport and discovery of a remarkable opposition surge: History of water in the inner solar system: The Leading Edge, 26, — Temporary pause or a new steady-state?: Geophysical Research Letters, 30, , doi: Geophysical Research Letters, 20, — A potential analog for methane production on Mars: Astronomy and Astrophysics, , A17, doi: Astronomy and Astrophysics, , A51, doi: Applied and Environmental Microbiology, 56 10 , — Astrophysical Journal, , — Physics of the Earth and Planetary Interiors, 15, — Planetary and Space Science, 48, — The Annual Review of Marine Science, 1, — Reports on Progress in Physics, 68, — Geophysical Research Letters, 33, L, doi: The Physical Science Basis: Journal of Geophysical Research, , — Reviews of Geophysics, 31, — Atmospheric Environment, 22, — Tellus B, 50, — The Messenger, , 20— Astronomy and Astrophysics, , L, doi: Thermodynamic Equilibrium and Photochemical Calculations.

Astrobiology Science Conference Memorie della Societa Astronomica Italiana Supplement, 19, 75— Geophysical Research Letters, 32, L, doi: The major organic carbon reserve of the Earth: Journal of Petroleum Science and Engineering, 56, 1—8. Journal of the Atmospheric Sciences, 26, — Detection of new hydrocarbons: Proceedings of the National Academy of Sciences, 47, — Astronomy and Astrophysics, 49 1 , — Evidence for Interstellar Origin, Science, , — Evidence for Surface Volatiles: Journal of Geophysical Research: Space Physics, 85 A13 , — Origins of Life, 5, — Journal of Geophysical Research, 85, — Serpentinization and the abiogenic production of methane on Mars: Annual Review of Earth and Planetary Sciences, 40, — Geophysical Research Letters, 16, — Astronomy and Astrophysics, , L13—L General, 1—2 , 3— Journal of Geophysical Research, , C, doi: Cambridge University Press, Cambridge, 59— Applications to the outer solar system: Journal of Geophysical Research, 92, — Geophysical Research Letters, 36, L, doi: Journal of Geophysical Research, , E, doi: Earth-Science Reviews, 57, — Astrophysical Journal Supplement Series, 55, — Experimental chondrules by melting samples of olivine, clays and carbon with a CO 2 laser.

Chondrules are the major constituents of chondritic meteorites; however, their origin is still an enigma for meteoritic science. In this work we report the results of melting minerals to experimentally generate objects similar to chondrules. The degree of fusion of olivine appears to be an important factor in determining the width of the bars in samples with barred-type olivine BO chondrules. On the other hand, the contribution of clays and carbon possible precursor grains is an important factor in those experiments where the melted samples showed porphyritic texture.

In meteoritic science one of the biggest enigmas is the formation of chondrules, the nature of the precursor materials, the physical conditions pressure, temperature and time and the generating mechanisms e. King, ; Boss, ; Rubin, ; Scott, ; Alexander et al. In order to obtain more information about the origin of chondrules, it is necessary to describe the petrology of natural chondrules to guide experiments that are expected to reproduce the textures of natural chondrules.

Through experimental research it is possible to simulate the conditions of melting of the chondrules and the type of cooling they have experienced. The objective of this paper is to report the results of the experimental use of radiation from an infrared laser to melt silicates, simulating the formation of chondrules barred and porphyritic types by rapid heating and cooling.

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We do not intend to make an exhaustive analysis of the formation mechanism or properties of precursors from the results presented here. Our experiments are the starting point to guide more detailed ones, where we will be able to control and measure the chemical properties and physical conditions pressure and temperature of the samples.

These guidelines are very important to constrain those variables that should be taken into account in our next set of experiments. We assume that the chondrules are formed by multiple heating steps Wasson, ; Rubin, , and that the presence of carbon-related material as a precursor is relevant Connolly and Hewins, ; Hewins, ; Connolly and Love,

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