organic chemistry Archives

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Imaging & Spectroscopy, Mars, Missions & Hardware, Origin & Evolution of Life, Press Release, Robotics/Rovers/UAVs, Sample Return

DNA Fragments Could Survive In Martian Rocks For More Than 100 Million Years

by Keith CowingMarch 24, 2026March 24, 2026

The Centro de Astrobiología (CAB), CSIC-INTA, has led a study published in Communications Earth and Environment, showing that if life had ever emerged on Mars, DNA fragments could be preserved […]

The network of important reactions for the carbon, sulfur, and coupled organosulfur chemistry in the atmosphere of K2-18b. Pathway B (following R. Hu et al. (2025)) dominates the DMS and DMDS production and is highlighted in green. Reaction steps in pathway A (following N. W. Reed et al. (2024)) that are not in pathway B are highlighted in grey. Destruction pathways of DMS and DMDS are highlighted in red. Unimolecular reactions are denoted with dashed lines, bimolecular reactions with solid single lines, and termolecular reactions with solid double lines. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Organosulfur Chemistry On sub-Neptunes: Implications For Hazes And Biosignatures

by Keith CowingMarch 22, 2026March 22, 2026

The organosulfur biosignature gases dimethylsulfide (DMS) and dimethlydisulfide (DMDS) have recently been claimed to be present in the atmosphere of sub-Neptune exoplanet K2-18b, leading to the suggestion of possible extraterrestrial […]

Eimission spectra of 3I/ATLAS taken with BFOSC and YFOSC. For clarity, the full spectral range is divided into three panels with different vertical offsets to emphasize specific features. The left panel highlights emission lines of Ni i (blue dashed lines) and Fe i (red dashed lines), and the CN violet band (blue shaded). The middle panel shows molecular bands of C3 (green shaded), CH (orange shaded), and C2 (red shaded), and lists the heliocentric distance for each spectrum. The right panel displays the [O i] λλ6300, 6364 doublet (green dashed lines). -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Post-perihelion Coma Composition Of The Interstellar Comet 3I/ATLAS From Optical Spectroscopy

by Keith CowingMarch 19, 2026March 19, 2026

We present multi-epoch optical spectroscopy of the interstellar comet 3I/ATLAS obtained from December 2025 to January 2026 (heliocentric distances 1.8 to 3.3 au). From these spectra, we derive post-perihelion production […]

(Left) Depiction of the hemibonded CN radical adsorbed on a 14 H2O cluster. (Right, Top) Parallel geometries for the approach of C2H2 and C2H4 to hemibonded CN. (Right, Bottom) Collinear geometries for the approach of C22H2 and C2H4 to hemibonded CN. All the structures are optimized and represent the actual reactant states used in the determination of the energetic descriptors of the reaction. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Can Cyanide Radicals Drive Molecular Backbone Growth On Interstellar Icy Grains?

by Keith CowingMarch 18, 2026March 18, 2026

Motivated by the value of CN-bearing molecules as tracers of interstellar physical conditions, we investigate the reactions of adsorbed CN radicals with acetylene and ethylene (C2H2 and C2H4) on interstellar […]

Left: integrated emission maps of the H2CO 4(0,4)-3(0,3) line for the observed sources. Right: peak intensity emission for the same line. Continuum emission at 0.8 mm contours is overlaid to compare with the formaldehyde emission in the disks. Beams are illustrated on the bottom-right with solid white for continuum images and dashed lines for line emission. The bottom-left bar represents a respective 100 au physical scale for each source. For most disks, there are no clear correspondences between the dust continuum contours and the integrated maps.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

exoALMA. XXIV. Formaldehyde Emission in Protoplanetary Disks of exoALMA Compared with Their Properties and Dynamical State

by Keith CowingMarch 17, 2026March 17, 2026

The presence of asymmetries and substructures in protoplanetary disks, revealed by both dust and gas emission, highlights the potential interplay and the broader connection between chemistry and dynamics in disk […]

A Representation of two possible evolution models of the RNA replication system containing two replicases and two parasites. B Illustration of the deterministic assumptions. C Transient compartmentalization with pooling (homogeneous case). D Illustration of the typical oscillatory dynamics obtained with the deterministic approach with second order replication rates and mutations. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Nanotechnology & SynBio, Status Report

Compositional Memory Matters For Early Molecular Systems

by Keith CowingMarch 16, 2026June 11, 2026

The error catastrophe refers to the proliferation of non-functional molecules in conditions where molecular replication has low accuracy, which is likely to correspond to conditions present at the Origin of […]

Comparison of various tracers of dust, gas, and extinction toward the CygX region. Cyan contours in all images indicate H2O ice peak optical depths of 0.25, derived from the H2O ice map smoothed with a Gaussian kernel of σ ∼ 31′′ (5 pixels). (a) 2MASS NICEST AJ extinction, with a resolution of 3′ . (b) FCRAO 13CO (1–0) Moment 0 map (beamsize 45′′ FWHM) integrated over −10 to +20 km s−1 , corresponding to the ensemble of star-forming molecular clouds directly associated with the Cyg OB2 cluster (N. Schneider et al. 2006). (c) Herschel-derived NH2 column density. (d) Herschel-derived dust temperature, Td. Both Herschel images are at a resolution of 36.4′′ -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Press Release

SPHEREx Wide-Field Infrared Spectral Mapping of Interstellar Ices and Polycyclic Aromatic Hydrocarbons

by Keith CowingMarch 16, 2026March 16, 2026

We present some of the first infrared spectral maps acquired by SPHEREx. These maps, which to our knowledge are the largest of their type ever compiled in the near-infrared, reveal […]

Microscope images of Ryugu samples collected from the first and second landing sites of the Hayabusa2 mission, respectively. Credit: Jaxa/Jamstec

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Genomics, Proteomics, Bioinformatics, Press Release

All DNA/RNA Nucleobases Are Found On Asteroid Ryugu

by Keith CowingMarch 16, 2026June 11, 2026

Samples from the asteroid Ryugu collected and returned to Earth by the Japanese Hayabusa 2 mission contain all five nitrogenous bases—adenine, guanine, cytosine, thymine, and uracil—that make up nucleic acids, […]

Stacked images of 3I/ATLAS acquired by HiRIC CMOS camera onboard Tianwen-1 spacecraft (upper row) and the corresponding 1/ρ divided images (lower row) from the three epochs. All images are displayed north up and east to the left. The stacked images are displayed with logarithmic brightness stretch, and the enhanced images are displayed with a linear brightness stretch. The arrows in the upper panels mark the projected directions of the Sun and the heliocentric velocity vector. The scalebars are 10,000 km. The bright star trails are visible in each stack due to the apparent movement of 3I in the sky background during each 30-second observation epoch. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Interstellar Object 3I/ATLAS Observed from Mars by China’s Tianwen-1 Spacecraft

by Keith CowingMarch 14, 2026March 14, 2026

China’s Tianwen-1 Mars orbiter successfully imaged the third interstellar object, 3I/ATLAS, during its close encounter with Mars using the onboard HiRIC CMOS camera. This is China’s first deep-space observation of […]

CH3OH/H2O column density ratio found in the literature for a wide range of clouds, YSOs and Solar System comets (see Sect 4.1 for the references). The values for molecular clouds, LYSOs and MYSOs reflect the ice composition, while the ratio was measured in the gas-phase for protoplanetary disks and comets. We used open symbols for the protoplanetary disks in which the upper/lower limit on the methanol-to-water column density ratio was estimated combining measurements taken at different wavelength ranges. The upward triangles for the HD 100546 and the IRS 48 disks indicate a lower limit, whereas the downward triangles for DG Tau A and HL Tau indicate a upper limit. The values for HL Tau are taken dividing the 3σ upper limit on the NCH3OH for the three different assumed excitation temperature in Table 2 for the water column density measured by Facchini et al. (2024). -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Hunting For Methanol In The Water Rich, Planet Forming Disk Aaround HL Tau

by Keith CowingMarch 13, 2026March 13, 2026

Methanol, the simplest complex organic molecule found in space, is considered a key compound necessary for the formation of chemical species of prebiotic interest. Methanol detections in protoplanetary disks remain […]

organic chemistry

DNA Fragments Could Survive In Martian Rocks For More Than 100 Million Years

Organosulfur Chemistry On sub-Neptunes: Implications For Hazes And Biosignatures

Post-perihelion Coma Composition Of The Interstellar Comet 3I/ATLAS From Optical Spectroscopy

Can Cyanide Radicals Drive Molecular Backbone Growth On Interstellar Icy Grains?

exoALMA. XXIV. Formaldehyde Emission in Protoplanetary Disks of exoALMA Compared with Their Properties and Dynamical State

Compositional Memory Matters For Early Molecular Systems

SPHEREx Wide-Field Infrared Spectral Mapping of Interstellar Ices and Polycyclic Aromatic Hydrocarbons

All DNA/RNA Nucleobases Are Found On Asteroid Ryugu

Interstellar Object 3I/ATLAS Observed from Mars by China’s Tianwen-1 Spacecraft

Hunting For Methanol In The Water Rich, Planet Forming Disk Aaround HL Tau

Isobaric Crystallization of Aqueous Magnesium Chloride Solutions at Icy Moon Conditions

Systematic Uncertainties in Rocky Exoplanet Reflected Light from Incomplete Laboratory BRDF Measurements

New Discovery Links Hemispheres In The Mystery Of Earth’s Past Ice Ages

UV Photodamage Pathways And The Evolutionary Selection Of Thymine Over Uracil In Early Genetic Systems

Reversion To The Meta Body Form Of Life After Complete Cell Death In Pure Liquid Water