Results 101 to 110 of about 2,232 (202)

Clumped Isotope Signatures of Abiotic Methane: The Role of the Combinatorial Isotope Effect

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 7, July 2024.
Abstract Methane clumped isotope signatures of abiogenesis may be diagnostic of the origin of methane on Earth and other planetary bodies. We performed synthesis of abiogenic methane in hydrothermal conditions between 130 and 300°C and determined δ13C, δD, Δ13CH3D, and Δ12CH2D2.
Jabrane Labidi, Thomas M. McCollom, Thomas Giunta, Barbara Sherwood Lollar, William D. Leavitt, Edward D. Young   +5 more
wiley   +1 more source

The Origin of Life from Primordial Planets

, 2010
The origin of life and the origin of the universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics (HGD) cosmology predicts hydrogen-helium gas planets in clumps as the dark matter of ...
Gibson, Carl H., Schild, Rudolph E., Wickramasinghe, N. C.   +2 more
core   +1 more source

Formation of Amino Acids and Carboxylic Acids in Weakly Reducing Planetary Atmospheres by Solar Energetic Particles from the Young Sun

Life, 2023
Life most likely started during the Hadean Eon; however, the environmental conditions which contributed to the complexity of its chemistry are poorly known.
Kensei Kobayashi, Jun-ichi Ise, Ryohei Aoki, Miei Kinoshita, Koki Naito, Takumi Udo, Bhagawati Kunwar, Jun-ichi Takahashi, Hiromi Shibata, Hajime Mita, Hitoshi Fukuda, Yoshiyuki Oguri, Kimitaka Kawamura, Yoko Kebukawa, Vladimir S. Airapetian   +14 more
doaj   +1 more source

A Prerequisite for Life [PDF]

Journal of Theoretical Biology 474, 48-51, (2019), 2019
The complex physicochemical structures and chemical reactions in living organism have some common features: (1) The life processes take place in the cytosol in the cells, which, from a physicochemical point of view is an emulsion of biomolecules in a dilute aqueous suspension.
arxiv   +1 more source

Evidence of Selection in Mineral Mediated Polymerization Reactions Executed in a Robotic Chemputer System

ChemSystemsChem, Volume 6, Issue 3, May 2024.
An automated platform explores the reactions of amino acids in the presence of mineral environments and searches for evidence of the onset of selection. The outcome of oligomerisation is significantly influenced by the presence of different minerals, with certain environments selecting specific fragments that enable the formation defined sequences as a
Silke Asche, Robert W. Pow, Hessam M. Mehr, Geoffrey J. T. Cooper, Abhishek Sharma, Leroy Cronin   +5 more
wiley   +1 more source

Enceladus: Astrobiology Revisited

Journal of Geophysical Research: Biogeosciences, Volume 129, Issue 5, May 2024.
Abstract Astrobiology research seeks to understand how life begins and evolves, and to determine whether life exist elsewhere in the universe. The discovery of diverse ocean worlds has significantly expanded the number of planetary bodies in the Solar System that could potentially contain life.
A. F. Davila, J. L. Eigenbrode
wiley   +1 more source

A Census of Near-UV M-dwarf Flares Using Archival GALEX Data and the gPHOTON2 Pipeline

The Astrophysical Journal, 2023
M-dwarfs are common stellar hosts of habitable-zone exoplanets. Near-UV (NUV) radiation can severely impact the atmospheric and surface conditions of such planets, making the characterization of NUV flaring activity a key aspect in determining ...
Param Rekhi, Sagi Ben-Ami, Volker Perdelwitz, Yossi Shvartzvald   +3 more
doaj   +1 more source

Atmospheric escape from the TRAPPIST-1 planets and implications for habitability [PDF]

Proceedings of the National Academy of Sciences, Vol. 115, 260-265 (2018), 2017
The presence of an atmosphere over sufficiently long timescales is widely perceived as one of the most prominent criteria associated with planetary surface habitability. We address the crucial question as to whether the seven Earth-sized planets transiting the recently discovered ultracool dwarf star TRAPPIST-1 are capable of retaining their ...
arxiv   +1 more source

Prebiotic Vitamin B3 Synthesis in Carbonaceous Planetesimals

ChemPlusChem, Volume 89, Issue 4, April 2024.
Aqueous chemistry inside meteorite parent bodies allows the formation of prebiotic molecules crucial for all life in the early solar system. We present a reaction mechanism suitable for vitamin B3 synthesis in this environment, which is experimentally verified in the literature.
Klaus Paschek, Mijin Lee, Dmitry A. Semenov, Thomas K. Henning   +3 more
wiley   +1 more source

Galactic Distribution of Chirality Sources of Organic Molecules [PDF]

, 2016
Conceptualizing planetary habitability depends on understanding how living organisms originated and what features of environments are essential to foster abiogenesis. Estimates of the abundance of life's building blocks are confounded by incomplete knowledge of the role of chirality and racemization in organic compounds in the origination of living ...
arxiv   +1 more source