Organic matter in space: from star dust to the Solar System

Kwok, Sun

doi:10.1007/s10509-008-9965-6

Cited by 51 publications

(37 citation statements)

References 110 publications

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“…Such a systematic study of the gasphase molecules presents an important step to understand the synthesis of more complex aromatic and aliphatic compounds in evolved stars, and their role in the distribution of organic compounds throughout the Galaxy (Kwok 2009). A detailed study of chemical processes in different physical conditions and evolutionary stages will be reported in the future.…”

Section: Discussionmentioning

confidence: 99%

A Molecular Line Survey of the Extreme Carbon Star CRL 3068 at Millimeter Wavelengths

Zhang

Kwok

Nakashima

2009

ApJ

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We present the results of a molecular line survey of the extreme carbon star CRL 3068. The observations were carried out with the Arizona Radio Observatory (ARO) 12 m telescope and the Heinrich Hertz Submillimeter Telescope (SMT) at the λ 2 mm and λ 1.3 mm atmospheric windows. The observations cover the frequency bands from 130 to 162 GHz and 219.5 to 267.5 GHz. The typical sensitivities achieved are T R < 15 mK and T R < 7 mK for the ARO 12 m and SMT, respectively. Seventy-two individual emission features belonging to 23 molecular species and isotopologues were detected. Only three faint lines remain unidentified. SiS, and 30 SiS are detected in this object for the first time. Rotational-diagram analysis is carried out to determine the column densities and excitation temperatures. The isotopic ratios of the elements C, N, O, S, and Si have also been estimated. The results are consistent with stellar CNO processing and suggest that CRL 3068 is more carbon rich than IRC+10216 and CIT 6. It is also shown that the chemical composition in CRL 3068 is somewhat different from that in IRC+10216 with a more extensive synthesis of cyclic and long-chain molecules in CRL 3068. The results will provide valuable clues for better understanding circumstellar chemistry.

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Section: Discussionmentioning

confidence: 99%

A Molecular Line Survey of the Extreme Carbon Star CRL 3068 at Millimeter Wavelengths

Zhang

Kwok

Nakashima

2009

ApJ

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“…In corroboration, it has been found that cosmic regions of high organic molecular densities are often associated with regions of stellar formation (Ehrenfreund and Charnley, 2000). Over 140 organic molecules have now been found in space, although the nucleobases have yet to be detected (Kwok, 2009). The dispersed organic molecules are then suggested to have been deposited into the Earth's oceans through the vehicle of colliding comets, asteroids, or space dust.…”

Section: Ambient Conditions Of Insipient Lifementioning

confidence: 92%

Thermodynamic dissipation theory for the origin of life

Michaelian

2011

Earth Syst. Dynam.

168

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Abstract. Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore available microstates. The most important irreversible process generating entropy in the biosphere and, thus, facilitating this exploration, is the absorption and transformation of sunlight into heat. Here we hypothesize that life began, and persists today, as a catalyst for the absorption and dissipation of sunlight on the surface of Archean seas. The resulting heat could then be efficiently harvested by other irreversible processes such as the water cycle, hurricanes, and ocean and wind currents. RNA and DNA are the most efficient of all known molecules for absorbing the intense ultraviolet light that penetrated the dense early atmosphere and are remarkably rapid in transforming this light into heat in the presence of liquid water. From this perspective, the origin and evolution of life, inseparable from water and the water cycle, can be understood as resulting from the natural thermodynamic imperative of increasing the entropy production of the Earth in its interaction with its solar environment. A mechanism is proposed for the reproduction of RNA and DNA without the need for enzymes, promoted instead through UV light dissipation and diurnal temperature cycling of the Archean sea-surface.

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“…Complex organic molecules are, in fact, ubiquitous throughout the cosmos and are formed basically by the action of UV light on simpler prebiotic organic and inorganic carbon compounds (Callahan et al, 2011;Kwok, 2009;Gerakines et al, 2004). Many species of organic molecules (especially those with conjugated systems -Zollinger, 2003) when dissolved in water are very efficient absorbers and dissipaters of UV and visible photons and should therefore be considered as organic pigments during the Hadean and Archean eons.…”

Section: World Of Earliest Pigments (Hadean Eonmentioning

confidence: 99%

Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum

Michaelian

Simeonov²

2015

Biogeosciences

112

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Abstract. The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate. In the upper atmosphere of today, oxygen and ozone derived from life processes are performing the short-wavelength UV-C and UV-B dissipation. On Earth's surface, water and organic pigments in water facilitate the near-UV and visible photon dissipation. The first organic pigments probably formed, absorbed, and dissipated at those photochemically active wavelengths in the UV-C and UV-B that could have reached Earth's surface during the Archean. Proliferation of these pigments can be understood as an autocatalytic photochemical process obeying non-equilibrium thermodynamic directives related to increasing solar photon dissipation rate. Under these directives, organic pigments would have evolved over time to increase the global photon dissipation rate by (1) increasing the ratio of their effective photon cross sections to their physical size, (2) decreasing their electronic excited state lifetimes, (3) quenching radiative de-excitation channels (e.g., fluorescence), (4) covering ever more completely the prevailing solar spectrum, and (5) proliferating and dispersing to cover an ever greater surface area of Earth. From knowledge of the evolution of the spectrum of G-type stars, and considering the most probable history of the transparency of Earth's atmosphere, we construct the most probable Earth surface solar spectrum as a function of time and compare this with the history of molecular absorption maxima obtained from the available data in the literature. This comparison supports the conjecture that many fundamental molecules of life are pigments which arose, proliferated, and co-evolved as a response to dissipating the solar spectrum, supports the thermodynamic dissipation theory for the origin of life, constrains models for Earth's early atmosphere, and sheds some new light on the origin of photosynthesis.

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Organic matter in space: from star dust to the Solar System

Cited by 51 publications

References 110 publications

A Molecular Line Survey of the Extreme Carbon Star CRL 3068 at Millimeter Wavelengths

A Molecular Line Survey of the Extreme Carbon Star CRL 3068 at Millimeter Wavelengths

Thermodynamic dissipation theory for the origin of life

Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum

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