Neptune’s present axial tilt of approximately 28 deg. with respect to its orbital plane can be explained by collisions that its primordial core may have experienced with surrounding planetary embryos […]
astro-ph.EP
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
TOI-4552 b: A New Ultra-short Period Rocky World Revealed By NIRPS And TESS
A particularly intriguing subclass of rocky exoplanets are the ultra-short period (USP) worlds that orbit their host stars in less than a day. These planets are particularly rare around M […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Exploring The Surface Of HD 189733 via Doppler Shadow Analysis Of Planetary Transits
Transmission spectroscopy has greatly advanced the study of exoplanet atmospheres, but stellar surface heterogeneities can contaminate transit spectra. Characterising how stellar spectra vary across the stellar disc is therefore essential […]
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Searching For Molecular Signatures In 14 Transiting Exoplanets With SPIRou
High-resolution spectroscopy provides unique constraints on exoplanet atmospheric composition and dynamics. The past decade of ground-based campaigns has accumulated extensive public archives, yet many observations remain unanalysed.
![Eimission spectra of 3I/ATLAS taken with BFOSC and YFOSC. For clarity, the full spectral range is divided into three panels with different vertical offsets to emphasize specific features. The left panel highlights emission lines of Ni i (blue dashed lines) and Fe i (red dashed lines), and the CN violet band (blue shaded). The middle panel shows molecular bands of C3 (green shaded), CH (orange shaded), and C2 (red shaded), and lists the heliocentric distance for each spectrum. The right panel displays the [O i] λλ6300, 6364 doublet (green dashed lines). -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/03/Postperihelion-Coma-Composition.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report
Post-perihelion Coma Composition Of The Interstellar Comet 3I/ATLAS From Optical Spectroscopy
We present multi-epoch optical spectroscopy of the interstellar comet 3I/ATLAS obtained from December 2025 to January 2026 (heliocentric distances 1.8 to 3.3 au). From these spectra, we derive post-perihelion production […]
Posted inAstrogeology, Biogeochemical Cycles & Geobiology, Status Report
The Efficient Delivery Of Highly-siderophile Elements To The Core Creates A Mass Accretion Catastrophe For The Earth
The excess abundance of highly siderophile elements (HSEs), as inferred for the terrestrial planets and the Moon, is thought to record a `late veneer’ of impacts after the giant impact […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
Constraining Small Planet Compositions for Future Missions
Accurate mass and radius measurements of small transiting exoplanets are essential for probing their compositions, formation histories, and potential habitability.
Posted inAstrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. VIII. Molecular Mapping Performance With JWST/MIRI MRS: VHS 1256 b As A Case Study
VHS 1256 b was the first planetary-mass companion to be observed with the James Webb Space Telescope’s Mid-Infrared Instrument (JWST/MIRI) using the Medium-Resolution Spectrometer (MRS).
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report
Isotopic Evidence For A Cold And Distant Origin Of The Interstellar Object 3I/ATLAS
Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during […]
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report
Ortho-Para Chemistry of H2CO in the Protoplanetary Disk TW Hya
The spatial distribution of the chemical reservoirs in protoplanetary disks is key to elucidate the composition of planets, especially habitable ones. However, the partitioning of the main elements among the […]