Publications by authors named "J P Dworkin"
Article Synopsis
- * The research simulated the aqueous alteration processes of residues from irradiated interstellar ice, using minerals like serpentinite and the Allende meteorite to study amino acid changes.
- * Results showed that minerals and their types crucially affect the creation and breakdown of amino acids during these simulated experiments.
Understanding how organics degrade under galactic cosmic rays (GCRs) is critical as we search for traces of ancient life on Mars. Even if the planet harbored life early in its history, its surface rocks have been exposed to ionizing radiation for about four billion years, potentially destroying the vast majority of biosignatures. In this study, we investigated for the first time the impact of simulated GCRs (using gamma rays) on several types of lipid biosignatures (including hopane C, sterane C, alkanes, and fatty acids [FAs]) in both the presence and absence of salts (NaCl, KCl, and MgCl).
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- Modern life is homochiral, meaning it primarily utilizes D-sugars in nucleic acids and L-amino acids in proteins, suggesting a significant evolutionary process.
- The concept of a prebiotic RNA World implies that L-amino acids arose due to chiral transfer from an earlier D-RNA World, facilitated by aminoacyl-RNAs that helped develop the genetic code.
- Research using D-ribozymes shows that while there is detectable chiral selectivity favoring certain enantiomers, it does not support the idea that D-RNA inherently prefers to react with L-amino acids, indicating that L-proteins can originate from different chiral contexts.
Returned samples from the carbonaceous asteroid (162173) Ryugu provide pristine information on the original aqueous alteration history of the Solar System. Secondary precipitates, such as carbonates and phyllosilicates, reveal elemental partitioning of the major component ions linked to the primordial brine composition of the asteroid. Here, we report on the elemental partitioning and Mg isotopic composition (Mg/Mg) of breunnerite [(Mg, Fe, Mn)CO] from the Ryugu C0002 sample and the A0106 and C0107 aggregates by sequential leaching extraction of salts, exchangeable ions, carbonates, and silicates.
View Article and Find Full Text PDFEuropa and Enceladus are key targets to search for evidence of life in our solar system. However, the surface and shallow subsurface of both airless icy moons are constantly bombarded by ionizing radiation that could degrade chemical biosignatures. Therefore, sampling of icy surfaces in future life detection missions to Europa and Enceladus requires a clear understanding of the necessary ice depth where unaltered organic biomolecules might be present.
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