![Benchmark test between chemcat (dashed black lines) and GGchem (solid colored lines) for a network of neutral species at 1 bar and temperatures from 100–6000 K (only selected species are shown). Both codes produced results typically consistent within 0.1 dex, with noticeable differences resulting from missing thermochemical data or at the lowest temperatures T ≲ 200 K. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Pyrat-Bay.png?resize=1200%2C713&ssl=1)
[astro-ph.EP] This article presents a major update to the open-source Pyrat Bay modeling framework (version 2.0), tailored for the characterization of exoplanet atmospheres with the observational capabilities of current facilities, […]
JWST
![Illustration of the VHS 1256 b data used in this study. (Top) Full ERS #1386 program (V2) spectrum of VHS 1256 b with overlapping wavelengths between orders shown in grey. With 12 spectral orders populating the NIRSpec and MIRI data combination we have 11 overlaps present across the global spectrum. (Middle) NIRSpec data at its native resolution and the binned spectrum used in our retrieval analysis. (Bottom) MIRI data at its native resolution and the binned spectrum used in our retrieval analysis. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-JWST.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems VIII: Patchy Forsterite and Enstatite Clouds in the Atmosphere of VHS 1256 b.
[astro-ph.EP] JWST defines a new era for the data-driven approach of retrieval modelling, which has become a cornerstone tool for the statistical inference of exoplanetary and brown dwarf properties.
![Illustration of the TRAPPIST-1 system and the most recent JWST constraints on planetary atmospheres. Planet size and distance roughly to scale. - [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/veiled.png?resize=1200%2C820&ssl=1)
Posted inTRAPPIST-1
Veiled in Starlight: Impacts of Stellar Contamination On Retrievals of TRAPPIST-1f’s Atmospheric Composition
[astro-ph.EP] The TRAPPIST-1 system offers seven terrestrial exoplanets with tight orbits and large radii ratios to the host star. If an atmosphere exists, transmission spectroscopy can be used to detect […]
Posted inAstronomy & Telescopes
Astrochemistry In Action: JWST View Of The Carina Nebula
[ESA] This NASA/ESA/CSA James Webb Space Telescope Picture of the Month takes us to a fantastical realm within our home galaxy, where piercing starlight and billowing winds sculpt dust clouds […]
Posted inAstrochemistry
Variations in the 3.3 µm Polycyclic Aromatic Hydrocarbon Feature Across Nearby Galaxies Driven by Metallicity and Radiation Field Spectrum
[astro-ph.GA] We use JWST NIRCam imaging to investigate the 3.3 μm polycyclic aromatic hydrocarbon (PAH) feature in nearby galaxies. NIRCam observations of the 3.3 μm feature are emerging as a […]
Posted inExoplanets, -moons, -comets
Exploration Of Exoplanet Atmospheres With The James Webb Space Telescope
[astro-ph.EP] The James Webb Space Telescope (JWST) is providing transformative characterization capabilities for the study of both transiting and directly imaged extrasolar planets. Observations deep into the infrared in the […]
Posted inExoplanets, -moons, -comets
JWST Transmission Spectroscopy Of TOI-3235 b: Challenges In Constraining Giant Planet Atmospheres Around M Dwarfs Amid Stellar Contamination
[astro-ph.EP] Giant planets orbiting low-mass M dwarfs challenge current planet formation theories, which predict that such planets are unlikely to form. Characterizing their atmospheres can provide key insight into their […]
![The band depths and centers of Callisto’s CO2 as measured at 4.25 µm for three viewing geometries. The trailing hemisphere and Asgard-centered data were previously published by Cartwright et al. (2024). The following geologic units are marked with symbols: Valhalla, ⋆ ; Asgard, ◦; Lofn/Heimdall, △. The sub-observer longitude of the observation is indicated in the panels. The projected angular size of Callisto varies slightly between each observation, so the spaxel scale is slightly different in each panel. The typical uncertainty in the band depth is ± 0.4%, while the band center is ±0.0006µm -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Callisto.png?resize=1200%2C709&ssl=1)
Posted inCallisto
Callisto From JWST: CO2-rich Terrain On The Leading Hemisphere And Global Patterns Of H2O Ice
[astro-ph.EP] We present maps of H2O, CO2, and a 4.57 um spectral feature across Callisto’s surface observed using the James Webb Space Telescope (JWST).
![Life 2.0 mission concept and simulated biosignature spectroscopy. The distributed array observes a common target with many one-meter telescope modules. The example spectra illustrate UV-optical atmospheric signatures and the simulated recovery of O₃, O₂, and H₂O after calibrated spectral co-addition. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Life-2.0.jpg?resize=1200%2C719&ssl=1)
Posted inBiosignatures & Paleobiology
Life 2.0: A Scalable Distributed Space-Telescope Array For Biosignature Spectroscopy
[astro-ph.IM] Answering the question “Are we alone?” requires atmospheric spectroscopy of nearby terrestrial planets. For an Earth–Sun analog, even the strongest transmission signals are expected to be of order 1 […]
Posted inComets and Asteroids
A JWST Study of Stardust. I. Infrared Spectroscopy of Comet 81P/Wild 2 and Overall Composition
[astro-ph.EP] We report observations of comet 81P/Wild 2, target of the Stardust sample return mission, on UT 2023 March 20 and 24 at a heliocentric distance (rH) of 1.85 au […]