icy world Archives - Page 16 of 36 - Astrobiology

The temperature versus depth and time for 𝜅 = 10−4 W m−1 K−1 , 10−3 W m−1 K−1, and 10−2 W m−1 K−1 (top, middle, and bottom panels). The sublimation temperatures of CO (30 K, dash), CO2 (80 K, dash-dot), and H2O (150 K, dot) are shown as white contours. The depth of heat penetration and volatile activation strongly depends on the thermal conductivity 𝜅. Note that the range of the 𝑦-axis is different for each panel. -- astro-ph.EP

Astrochemistry, Astrogeology, Astropharmacy / Biotechnology, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Potential Thermal Profiles of The Third Interstellar Object 3I/ATLAS

by Keith CowingNovember 3, 2025November 3, 2025

We investigate the thermal evolution of 3I/ATLAS, the third macroscopic interstellar object discovered on 2025 July 1.

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 […]

Illustration of atmosphere–mantle–core coupling across rocky embryos to gas-rich planets. Mantle convection acts as a planetary-scale “conveyor belt,” facilitating chemical communication between the atmosphere and the core. The efficiency of this volatile cycling—potentially probed by the He 1083 nm feature, especially when combined with H Lyman-α—depends on the partition coefficients derived in this study. It governs the redistribution of H and He, the timescale of primordial atmosphere retention, aspects of redox balance in secondary atmospheres, and model predictions for the abundances of atmospheric CHNOPS species, ultimately shaping the H-to-He ratio in the atmospheres of Earth- to Neptune-like planets. -- physics.ao-ph

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Ice Giant, Icy Worlds, Neptune, Status Report, Water/Hycean Worlds & Oceanography

The Fate of Hydrogen and Helium: From Planetary Embryos to Earth- and Neptune-like Worlds

by Keith CowingNovember 3, 2025November 3, 2025

Hydrogen, helium, silicates, and iron are key building blocks of rocky and gas-rich planets, yet their chemical interactions remain poorly constrained.

In this image from Cassini, backlighting from the Sun spectacularly illuminates Enceladus' jets of water ice. NASA/JPL-Caltech/SSI

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Icy Worlds, Status Report, Video, Audio, Webcasts, Podcasts

Europlanet Webinar: Cassini Detects Organic Compounds in the Fresh Plume of Enceladus

by Keith CowingNovember 3, 2025November 3, 2025

5 November 2025 at 11:00 CET (10:00 UTC) Speaker: Thomas O’Sullivan, FU Berlin

We show the total surface flooding for a given topography as a function of Mg/Si and FeO for a 1 M⊕ planet with Earth-like molar ratios (i.e., Fe/Mg, Ca/Mg, Al/Mg). We use cubic interpolation between data points for smoothing. The colorbar indicates the surface flooding in Earth oceans. We show the compositions of solar system planets with the following notation: Earth (⊕), Venus (♀), Mars (♂), Mercury ('), using compositional values from R. G. Trønnes et al. (2019). (A) Earth-like topography shows three distinct ”islands” correspond to the increase in water storage capacity. (B) Venus-like and (C) Mars-like topographies show similar structure in the water coverage fraction. (D) Mercury-like topography reaches complete flooding at low OM. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

From Underground Oceans To Continents: A Glimpse Into The Water Inventory On Rocky Planets Using Host Star Abundances

by Keith CowingOctober 31, 2025October 31, 2025

The amount of surface water is thought to be critical for a planet’s climate stability and thus habitability.

Spatiotemporal Impacts of Enceladus- and Earth-relevant Ammonia Gas On Cultivation of Extremophile Halomonas meridiana

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Extremeophiles and Extreme Environments, Habitable Zones, Icy Worlds, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

Spatiotemporal Impacts of Enceladus- and Earth-relevant Ammonia Gas On Cultivation of Extremophile Halomonas meridiana

by Keith CowingOctober 28, 2025October 28, 2025

One underexplored aspect of microbial growth is the impact of toxic gases transported through the atmosphere. Ammonia is a gas that can supply essential nitrogen but also exert cellular toxicity.

The Discovery Building at Rothera Research Station, Antarctica. Image credit: BAM

Analog Studies, Arctic / Antarctic / Alpine, Away Teams & Field Reports, Cryobiology, Exploration Gear & Tech, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Polar / Alpine Expeditions, Press Release

Ice Planet Research: British Antarctic Survey Discovery Building Comes To Life

by Keith CowingOctober 27, 2025October 27, 2025

The 2025 – 2026 Antarctic season is a landmark for the British Antarctic Survey (BAS) and its Antarctic Infrastructure Modernisation Project (AIMP), as the new Discovery Building begins to take […]

Schematic diagram of the AQUILA chamber. Science Direct

Astrochemistry, Astrogeology, Enceladus, Icy Worlds, Imaging & Spectroscopy, Radiation, Saturn, Status Report

Water-group Ion Irradiation Studies Of Enceladus Ice Analogues: Can Radiolysis Account For Material In And Around The South Polar Plume?

by Keith CowingOctober 27, 2025October 27, 2025

Saturn’s magnetosphere contains trapped plasma and energetic charged particles which constantly irradiate the surface of Enceladus.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Status Report

The First Detection of Molecular Activity in the Largest Known Oort Cloud Comet: ALMA Imaging of C/2014 UN271 (Bernardinelli–Bernstein) at 16.6 au from the Sun

by Keith CowingOctober 24, 2025October 22, 2025

We report observations of comet C/2014 UN271 (Bernardinelli–Bernstein) carried out on UT 2024 March 8 and 17 at a heliocentric distance (rH) of 16.6 au using the Atacama Large Millimeter/submillimeter […]

Scanning electron microscopy images showing representative regions of desiccated salt samples. Top row: Flash frozen; bottom row: slow frozen. (a) NaCl flash frozen, (d) NaCl slow frozen; (b) Na2SO4 flash frozen, (e) Na2SO4 slow frozen; (c) Na2CO3 flash frozen, (f) Na2CO3 slow frozen. -- JGR Planets

Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Ceres, Enceladus, Europa, Habitable Zones, Icy Worlds, Robotics/Rovers/UAVs, Status Report, Water/Hycean Worlds & Oceanography

Microstructure Controls Sublimation Timescales of Exposed Salt-Rich Ices on Icy Worlds

by Keith CowingOctober 23, 2025October 22, 2025

Salt-rich water ice at the surfaces of icy worlds, for example, Europa, Enceladus, and Ceres, is of particular interest for Solar System exploration as it can represent a record of […]