carbonaceous meteorite Archives - Astrobiology

Orthographic projection of ISS data (Karkoschka et al. 2017) for Selk-centered hemisphere. (dashed inset) SAR regional mosaic colored with elevation data from Corlies et al. (2017). Source: Selection and Characteristics of the Dragonfly Landing Site near Selk Crater, Titan, The Planetary Science Journal

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Origin & Evolution of Life, Robotics/Rovers/UAVs, Status Report, Titan, Tricorders & Sensors

Prebiotic Chemistry Insights for Dragonfly II: Thermodynamic Favorability of Nucleobases, Ribose, and Fatty Acids in Selk Crater on Titan

by Keith CowingApril 20, 2026April 20, 2026

Saturn’s moon Titan is a prime destination for investigating prebiotic chemistry beyond Earth, particularly at impact crater sites where transient liquid water may have enabled aqueous reactions between organic molecules.

Proposed formation pathways of biorelevant molecules (red arrows) in hydrogen cyanide (HCN)-containing interstellar ices and their role as precursors to biorelevant molecules such as amino acids and nucleobases. In prebiotic chemistry, hydrogen cyanide (1) plays a fundamental role in the synthesis of amino acids such as glycine (2) and nucleobases including adenine (3) (bold black arrows) and guanine (4) through nonequilibrium chemistry. Notably, 5, 11, 14–16, and 18 have been detected in the interstellar medium; 2–4 have been identified in carbonaceous asteroid Bennu and various chondrites like Murchison meteorite. -- Chemical Science

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Status Report

Abiotic Formation Of Nitrile Precursors To Amino Acids And Nucleobases In Interstellar Ice Analogues

by Keith CowingJanuary 30, 2026June 10, 2026

Amino acids and the five canonical nucleobases have been identified in carbonaceous meteorites such as Murchison and Murray; however, their formation mechanisms under interstellar conditions have remained largely elusive.

Artistic depiction of liposome formation and evolution. Liposomes formed on the surface of the Archean water pools are destroyed by Solar UV unless they acquire two adaptive traits – the heavy content that sinks the liposomes to the bottom of the pool and facilitates protection from UV, and the formation of resilient autocatalytic membrane composition that ensures liposomal survival, fusion, fission, and mutation of the components, thus providing liposomes adaptation and persistence. -- q-bio.PE

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Microbiology & Virology, Origin & Evolution of Life, Status Report

Heuristic Model On The Origin Of The Homochirality Of Life

by Keith CowingJanuary 2, 2026January 3, 2026

Life demonstrates remarkable homochirality of its major building blocks: nucleic acids, amino acids, sugars, and phospholipids. We propose a mechanism that places the root of life homochirality in the formation […]

Isovaline -- Wikipedia

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Meteorites & Asteroids, Status Report

On The Correlation Between the Enantiomeric Excess of L-isovaline and the Level of Aqueous Alteration in Carbonaceous Meteorites

by Keith CowingJuly 7, 2024July 6, 2024

A positive correlation was observed between the enantiomeric excess (ee) of L-isovaline (L-iVal) and the degree of aqueous alteration (AqA) of carbonaceous meteorites. The origin of this remarkable phenomenon has […]