Radiation – Page 3 – My WordPress Site

Schematic diagram of typical initial conditions for a model run (not to scale). Temperature ranges from 100 to 273 K and is shown according to the color scale at right. There is an axis of symmetry on the right-hand side, adjacent to the denser and weaker “drip nucleus” region. The size, shape, density, and viscosity of the drip nucleus is varied between runs. Points labeled “X1,” “X2,” and “Y1” represent the locations of particle tracers tracked in Section 3 (results). Note that tracer particle “Y1” is at 300 m depth below the surface of the shell. Inset: depiction of “tapered” drip shape modeled in Section 4.2, with associated tracer particle locations. Inset shows the drip nucleus lithosphere against the symmetry boundary at the top of the model domain. -- The Planetary Science Journal

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Jupiter, Origin & Evolution of Life, Radiation, Water/Hycean Worlds & Oceanography

Study Suggests A Pathway For Life-sustaining Conditions In Europa’s Ocean

by Keith CowingJanuary 21, 2026January 21, 2026

Deep layers of molten rock inside some super-earths could generate powerful magnetic fields—potentially stronger than Earth’s—and help shield these exoplanets from harmful radiation. (University of Rochester Laboratory for Laser Energetics illustration / Michael Franchot)

Atmospheres, Climate, Weather, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Magnetic Fields, Electromagnetism, bioelectricity,, Radiation

Hidden Magma Oceans Could Shield Rocky Exoplanets From Harmful Radiation

by Keith CowingJanuary 21, 2026January 21, 2026

Astropharmacy / Biotechnology, Commercial & Private Sector, Genomics, Proteomics, Bioinformatics, Nanotechnology & SynBio, Radiation, Space Physiology & Medicine

Artemis II AVATAR (A Virtual Astronaut Tissue Analog Response)

by Keith CowingJanuary 20, 2026January 20, 2026

Hydrodynamic models of the τ Ceti astrosphere, assuming stellar mass loss rates of M˙= 0.03 M˙⊙ (left) and M˙= 0.1 M˙⊙ (right). The top panels show neutral H density and the bottom panels show proton temperature. The termination shock and astropause boundaries are labeled in the plasma temperature panel. The LOS to the star is indicated, at 59◦ from the upwind direction of the ISM flow. Dashed circles schematically indicate the spatial extent of τ Ceti’s debris disk, demonstrating that the disk will be at least partly exposed to the ISM outside the astropause, regardless of how the disk is actually oriented relative to the astrospheric structure. -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Radiation, Space Weather & Heliophysics, tau Ceti

HST Observations of HD 166620 and Tau Ceti: First UV Spectra of a Magnetic Grand Minimum Star and the Extent of Tau Ceti’s Astrosphere

by Keith CowingJanuary 16, 2026January 16, 2026

Stellar SEDs for α Cen A (blue) and B (orange) binned to 1 ˚A. The SED of the Sun, scaled to a distance of 1.33 pc, from Woods et al. (2009) is shown in gray for comparison. Colored background regions show the various regions described in §5.2. The regions containing the reconstructed Lyα (1214–1217 ˚A, §5.2.4) and SISTINE detector gap (1270–1300 ˚A, §5.2.3) are not colored for clarity. The PHOENIX model extends to 107 ˚A but we have restricted the Y axis to 10−17 erg s−1 cm−2 ˚A −1 , again to aid visual clarity of features within the main spectra. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Radiation, Space Weather & Heliophysics

Investigating the High-energy Radiation Environment of Planets in Sun-like Binary Systems

by Keith CowingJanuary 13, 2026January 13, 2026

Artist's rendition of the space weather around M dwarf TIC 141146667. The torus of ionized gas is sculpted by the star's magnetic field and rotation, with two pinched, dense clumps present on opposing sides of the star. Credit llustration by Navid Marvi, courtesy Carnegie Science.

Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Stellar Cartography

Naturally Occurring “Space Weather Station” Elucidates New Way To Study Habitability Of Planets Orbiting M Dwarf Stars

by Keith CowingJanuary 8, 2026January 8, 2026

The incident photon flux density for the modern-day Earth (black), Archean Earth at 2.65 Ga (blue), and TRAPPIST-1e (red). The spectral resolution has been reduced for clarity. The shaded regions represents three relevant bandpasses for photosynthesis: standard PAR (0.40-0.70 µm), extended PAR (0.40-0.75 µm), and anoxic PAR (0.40-1.1 µm). -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Origin & Evolution of Life, Radiation, Space Weather & Heliophysics, Terraforming & Geoengineering, TRAPPIST-1

Dearth of Photosynthetically Active Radiation Suggests No Complex Life on Late M-Star Exoplanets

by Keith CowingJanuary 7, 2026January 7, 2026

Illustration of flare heating in three types of stars. The dashed line marks the stellar surface; blue areas show the quiet atmosphere, and red areas show regions heated during a white-light flare. Vertical arrows indicate the radiative output, with length proportional to intensity. In solar-like stars (left), heating is regulated by hydrogen ionization, which limits temperatures of white-light flares to ∼ 9000 K. In late M dwarfs like TRAPPIST-1 (middle), molecular hydrogen dissociation acts as a thermostat, capping temperatures of white-light flares near ∼ 3500 − 4000 K. In early M dwarfs (right), insufficient concentration of H2 means the dissociation thermostat is ineffective, allowing higher white-light flare temperatures. -- astro-ph.SR

Exoplanets, -moons, -comets, Radiation, Space Weather & Heliophysics, TRAPPIST-1

Molecular Hydrogen Controls The Temperatures Of Flares On TRAPPIST-1

by Keith CowingJanuary 6, 2026January 6, 2026

This image from a map of Jezero Crater shows the area NASA’s Perseverance Mars rover is currently exploring, including Belva Crater, just below the center of the image. Credit: NASA/JPL-Caltech/University of Arizona/USGS-Flagstaff/JHU-APL -- NASA Larger image

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Mapping, Geodesy, Cartography, Mars, Missions & Hardware, Radiation, Robotics/Rovers/UAVs, Sample Return

Recent Production Rates Of Cosmogenic Nuclides In The Igneous Rocks of Jezero Crater Floor, Mars

by Keith CowingJanuary 2, 2026January 2, 2026

Cladosporium sphaerospermum (UAMH 4745) on potato dextrose agar after incubation for 14 days at 25°C. -- Wikipedia

Away Teams & Field Reports, Extremeophiles and Extreme Environments, Microbiology & Virology, Planetary Protection & Biosafety, Radiation, Sample Return

Fungi From Chernobyl: Mycobiota Of The Inner Regions Of The Containment Structures Of The Damaged Nuclear Reactor

by Keith CowingDecember 30, 2025December 30, 2025