[astro-ph.EP] Sulfur chemistry has emerged as an important probe of exoplanet atmospheres in the JWST era, although observational constraints have thus far been largely limited to SO2 and H2S in […]
Photochemistry
Posted inOrigin & Evolution of Life
Abiotic Sources Of Fixed Nitrogen Sustained Early Ecosystems For Several Hundred Million Years After The Origin Of Life
Nitrogen (N) plays a crucial role in controlling biological productivity. However, it remains unknown how Earth’s earliest ecosystems accessed bioavailable forms of nitrogen.
Posted inAtmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Photochemical CS2 Gas Detected On A 20-Myr-old Exoplanet
Probing the atmospheres of young exoplanets offers a powerful window into how planetary systems evolve and the physical and chemical processes that drive those early evolutions.
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Icy Worlds, Saturn, Status Report, Titan, Water/Hycean Worlds & Oceanography
Titan’s Organic World
Titan, Saturn’s largest moon, possesses a dense N2–CH4 atmosphere driving complex organic chemistry. The interplay among photochemistry, aerosol formation, organic cloud condensation, and surface deposition makes Titan a natural laboratory […]
Posted inAstronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
The First Remotely Detected Biosignature May Not Be the Most Common: Implications for JWST and HWO
The first detected member of a new astronomical class is often not representative of the underlying population, but instead reflects the selection effects of the observing technique that found it.
Posted inAstrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Status Report, TRAPPIST-1
Coupled Photochemical-Climate Modeling of Plausible Tenuous Outgassed Atmospheres on the TRAPPIST-1 Planets
Available JWST observations TRAPPIST-1 system have suggested that several of the planets are likely airless, or possess a very tenuous atmosphere.
Posted inBiophysics, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report
Flare-driven Habitability: Expanding Life’s Potential Around Low-mass Stars
The traditional definition of the circumstellar habitable zone (HZ) focuses on liquid water, but neglects the crucial role of ultraviolet (UV) radiation in prebiotic chemistry.
Posted inBiochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
Toward Inferring the Surface Fluxes of Biosignature Gases on Rocky Exoplanets from Telescope Spectra
The James Webb Space Telescope and the future Habitable Worlds Observatory aim to discover exoplanet atmospheric spectra that detect life. Currently, most existing spectral “retrieval” algorithms focus on inferring the […]
![2D color map as a function of Teq and [M/H]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/04/Sub-Neptunes-as-Soot.png?resize=1200%2C710&ssl=1)
Posted inAstrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Sub-Neptunes As Soot Factories: Deep Atmosphere Hydrocarbon Formation and Quenching as the Origin of Sub-Neptune Aerosol Trends
Recent population-level studies of sub-Neptune atmospheres have identified a parabolic trend in transmission spectrum amplitude for planets with Teq ~ 500-800 K. While the trend has been commonly attributed to […]
Posted inAtmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Plant Biology, Status Report
Photosynthetic Exergy I. Thermodynamic Limits For Habitable-zone Planets
Photosynthesis is central to Earth’s biosphere and a prime candidate for sustaining complex life on habitable exoplanets, yet a thermodynamically consistent treatment of the work potential of stellar radiation at […]