galactic cosmic rays Archives

Graphical Abstract -- ACS Central Science

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Sample Return, Status Report

The Formation of Glycolamide on Interstellar Ices

by Keith CowingMay 7, 2026May 7, 2026

For decades, scientists have searched interstellar space for the chemical seeds of life. In this issue of ACS Central Science, Kaiser and co-workers (1) offer a striking advance in that […]

Two-dimensional wireframe representation of the atmospheric geometry implemented in the Geant4 simulations. The model consists of four concentric spherical layers corresponding to the altitude ranges 15–20 km, 20–25 km, 25–30 km, and 30–35 km, surrounding the Earth’s surface. -- astro-ph.HE

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report

Energy Deposition By Galactic Cosmic Rays And Implications For Ozone Chemistry

by Keith CowingMarch 2, 2026March 2, 2026

We present a Monte Carlo study of galactic cosmic-ray (GCR) energy deposition and its implications for stratospheric chemistry, performed with the Geant4 toolkit.

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.

Heliosphere 2-3 Myr ago –speed. (a) meridional plane (b) equatorial plane showing the trajectory of Earth. When Earth will be inside the heliosphere the Galactic Cosmic Rays will be filtered by the heliosphere and there will be an increase of HEPs. (c) zoom of panel b on the termination shock. The termination shock at these small distances is a parallel shock. -- astro-ph.EP

Astrochemistry, Interstellar, Radiation, Space Weather & Heliophysics, Status Report, Stellar Cartography

Increased And Varied Radiation During The Sun’s Encounters With Cold Clouds In The Last 10 Million Years

by Keith CowingJanuary 27, 2026January 27, 2026

Recent research raises the possibility that 3 and 7 million years ago, the Sun encountered massive clouds that shrank the heliosphere–the solar cocoon protecting our solar system–exposing Earth to its […]

Schematic illustration of interstellar comet 3I/ATLAS showing the expected stratigraphy of an irradiated nucleus. Galactic cosmic ray irradiation over several Gyr alters the outer ∼15–20 m, producing a CO2-rich crust through CO-to-CO2 conversion, ongoing CO release from the breakdown of irradiated organics, an organic-rich refractory mantle with a red spectral slope, and compact amorphous ice characterized by low diffusivity and high thermal conductivity. Beneath this layer lies a pristine, unprocessed interior shielded from GCRs, whose composition and structure remain unknown but are expected to differ markedly from the irradiated crust. -- astro-ph.EP

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

Interstellar Comet 3I/ATLAS: Evidence for Galactic Cosmic Ray Processing

by Keith CowingNovember 3, 2025November 3, 2025

Spectral observations of 3I/ATLAS (C/2025 N1) with JWST/NIRSpec and SPHEREx reveal an extreme CO2 enrichment (CO2/H2O = 7.6+-0.3) that is 4.5 sigma above solar system comet trends and among the […]

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

Formation Of Thiocarbonic acid (H2CS3) – The Sulfur Counterpart Of Carbonic Acid (H2CO3) – In Interstellar Analog Ices

by Keith CowingSeptember 24, 2025September 26, 2025

The first experimental formation of thiocarbonic acid (H2CS3) is presented in this work from low-temperature interstellar ice analogs composed of hydrogen sulfide (H2S) and carbon disulfide (CS2) exposed to electron […]

Visualization of some of the effects of cosmic rays on the DNA of microorganisms and a simplified theory of the process of the double-strand break DNA repair mechanism which causes frequent gene mutations. -- astro-ph.HE

Microbiology & Virology, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

Galactic Forcing Increases Origination Of Marine Microplankton

by Keith CowingSeptember 5, 2025September 18, 2025

The continuous flux of Galactic cosmic rays that bombard Earth’s atmosphere creates ionizing radiation that can damage the DNA of living organisms.

The astrosphere of LHS 1140 compared to the heliosphere (left; e.g., Herbst et al. 2020b) with a zoom-in (right) showing the astrosphere of LHS 1140 in comparison to the Solar system. Shown is the number density in units of cm−3 . Colors are not to scale. -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Radiation, Space Weather & Heliophysics, Status Report

Modeling the astrosphere of LHS~1140

by Keith CowingDecember 11, 2024December 11, 2024

The cosmic ray (CR) flux, as well as the hydrogen flux into the atmosphere of an exoplanet, can change the composition of the atmosphere. Here, we present the CR and […]

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Cryobiology, Icy Worlds, Imaging & Spectroscopy, Missions & Hardware, Radiation, Status Report

Ionizing Radiation Exposure On Arrokoth Shapes A Sugar World

by Keith CowingDecember 9, 2024December 9, 2024

The flyby of the New Horizons spacecraft of the Kuiper Belt Object Arrokoth revealed its reddish appearance and unraveled the unexpected presence of a methanol-rich surface.