Astrochemistry Archives

ASPECS-6: Spectral fit using the full JWST/MIRI MRS wavelength coverage (light grey), together with the available photometric data (black crosses, see Sect. 3). The green line represents the total fit. The dark gray line shows the underlying continuum made of the cold dust (blue), cool dust (cyan), warm dust (orange), and hot dust component (not shown). The purple lines are the PAHs. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

PAHSPECS: Polycyclic Aromatic Hydrocarbon Properties At Cosmic Noon With JWST/MIRI MRS

by Keith CowingJune 18, 2026June 18, 2026

Context. Cosmic noon (z ~ 1-3) marks the peak of the cosmic star-formation rate density, when dust-obscured star formation dominated galaxy growth. Mid-infrared spectroscopy probes the interstellar medium through PAH […]

PAH ratio maps for the five PAHSPECS galaxies. We only show pixels that have a > 3σ measurement of the ratio. The left column shows NIRCAM color images using the F090W, F200W, F444W filters (M. J. Rieke et al. 2023). The second column shows the PAH6.2/PAH7.7 ratio. The third column shows the PAH11.3/PAH7.7 ratios. The fourth column shows the PAH3.3/PAH11.3 ratios. The final column shows [ArII]/PAH6.2. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

PAHSPECS: Spatially Resolved PAH Spectroscopy At Cosmic Noon With JWST MIRI MRS

by Keith CowingJune 18, 2026June 18, 2026

We present spatially resolved spectroscopy with JWST/MIRI MRS of a representative sample of normal star-forming galaxies at z∼1.1 as part of the PAHSPECS program.

An X-ray image of NWA 12774. (Credit: Aaron Bell/CU Boulder)

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Impact events, Meteorites & Asteroids, Press Release, Sample Return

Rare Meteorite Provides Evidence Of A Giant Early Planet

by Keith CowingJune 17, 2026June 17, 2026

Four-and-a-half billion years ago, a massive world, possibly as big as the moon or even Mars, orbited our sun before crashing into another celestial body and shattering into rubble.

An artist’s rendition of Saturn’s moon Enceladus depicts hydrothermal activity on the seafloor and cracks in the moon’s icy crust that allow material from the watery interior to be ejected into space. New research shows that instruments destined for the next missions could find traces of a single cell in a single ice grain contained in a plume. NASA/JPL-Caltech

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Icy Worlds, Status Report

Tidal Rock Grinding As A Source Of H2 On Enceladus

by Keith CowingJune 16, 2026June 16, 2026

The Solar System hosts multiple potentially habitable environments, including the subsurface ocean beneath the icy crust of Saturn’s moon Enceladus.

Analysis pipeline employed in the present work.

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Habitable Zones, Status Report

Reflections of Life: Distinguishing Living from Nonliving Worlds with Complexity Metrics

by Keith CowingJune 14, 2026June 14, 2026

Detecting life beyond Earth is the primary goal of astrobiology. In this study, we showcase the effectiveness of information and complexity-based metrics for detecting signs of life on exoplanets.

GLS periodograms of individual wavelength contrast lightcurves. In each of the panels, the light pink, dark pink, and black highlighted lines are the 1st, 2nd, and 3rd 12CO bandheads, respectively. The grey horizontal lines indicate the 1%, 5%, and 10% false alarm probabilities. The black vertical lines indicate the expected rotation period at 8.7 hrs and its first integer harmonic at 4.35 hrs. The top panel shows the uncorrected periodogram, with all wavelengths significantly affected by systematic effects caused by the fibre coupling. The middle panel shows the periodogram after the polynomial correction, while the bottom panel adds Gaussian smoothing to this to highlight strong periodic signals. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Beta Pictoris, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

13CO And Potential Variability In β Pictoris b With GRAVITY+

by Keith CowingJune 14, 2026June 14, 2026

The 12CO/13CO ratio was introduced as an indicator for where in the disk a planet has formed. Previously a lower value compared to the host star’s was suggested to show […]

Locations of the four candidate sites across a 2D map projection of Bennu’s surface captured by the OSIRIS-REx Camera Suite (OCAMS) (Bennett et al., 2021).

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Missions & Hardware, Sample Return, Status Report

Quantifying Surface Heterogeneity Across Asteroid (101955) Bennu using Candidate Site Remote Sensing Data

by Keith CowingJune 13, 2026June 13, 2026

The OSIRIS-REx mission acquired spatially resolved (2-10 m spot sizes) visible-near infrared (VNIR) and thermal infrared (TIR) spectra across four candidate sampling sites on asteroid (101955) Bennu: Nightingale, Osprey, Sandpiper, […]

Carbon isotope ratio as a function of the semi-major axis for young, directly-imaged companions. Measurements in the HR 8799 system for planets e, b, and c (Ruffio et al. 2026) are shown with squares and connected with a dotted line. The other measurements are for HD 984 b (Costes et al. 2024), GQ Lup b (González Picos et al. 2025b), VHS 1256 b (Gandhi et al. 2023), YSES 1 b (Zhang et al. 2024), AB Pic b (Gandhi et al. 2025), and DH Tau b and HIP 79098 b (Xuan et al. 2024a). The present-day local ISM (12C/13C = 68±14; Milam et al. 2005) and solar photospheric value (12C/13C⊙ = 91.4 ± 1.3; Lyons et al. 2018) are overlaid. The horizontal line spans the typical CO snow-line location for a solar-type host star (22–36 au). For stars hotter than the Sun, the CO snow line is expected at distances greater than 30 au, so β Pic b is located interior to the CO snow line. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

The Carbon Isotope Ratio Of β Pic b With High-resolution Spectroscopy

by Keith CowingJune 13, 2026June 13, 2026

Isotopic ratios trace the formation and evolution of planets and link their atmospheres to the chemistry of their natal protoplanetary discs.

Simulated multiband light-curve populations in the Cchroma–Ccross diagnostic plane. Left: noise-dominated, natural, and coherent variability classes (N ≈ 167 each, 500 total); ellipses show population covariance, open circles mark centroid-nearest examples. Right: normalised Rubin/LSST g, r, i light curves for those examples; coherent case shows stable cross-band structure, natural case shows stochastic variability, noise case is dominated by incoherent fluctuations. -- astro-ph.IM

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, SETI & Technosignatures, Status Report

Prospects for Astrobiology And Technosignature Searches With The Vera C. Rubin Observatory Legacy Survey Of Space And Time

by Keith CowingJune 12, 2026June 12, 2026

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will map sources in multiband colour–variability space.

NIRSpec average spectrum of Titan (black) compared with a radiative transfer calculation in which the surface albedo decreases smoothly with wavelength beyond 4.9 µm (red). The blue line shows the difference between the observed and synthetic spectra, shifted by 0.005 for clarity. The 5.11-µm absorption is clearly missing in the model. The small mismatch below 4.93 µm is due to a component of the non-LTE CO emission not included in the model. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Pluto, Status Report, Titan

An Unidentified Absorption Feature At 5.11 μm On The Surface Of Titan And Pluto From JWST Spectroscopy

by Keith CowingJune 12, 2026June 12, 2026

Titan possesses a thick N2-CH4 atmosphere that makes it difficult to study its surface spectroscopically. The chemical composition of the solid surface of Titan thus remains very uncertain.

Astrochemistry

PAHSPECS: Polycyclic Aromatic Hydrocarbon Properties At Cosmic Noon With JWST/MIRI MRS

PAHSPECS: Spatially Resolved PAH Spectroscopy At Cosmic Noon With JWST MIRI MRS

Rare Meteorite Provides Evidence Of A Giant Early Planet

Tidal Rock Grinding As A Source Of H2 On Enceladus

Reflections of Life: Distinguishing Living from Nonliving Worlds with Complexity Metrics

13CO And Potential Variability In β Pictoris b With GRAVITY+

Quantifying Surface Heterogeneity Across Asteroid (101955) Bennu using Candidate Site Remote Sensing Data

The Carbon Isotope Ratio Of β Pic b With High-resolution Spectroscopy

Prospects for Astrobiology And Technosignature Searches With The Vera C. Rubin Observatory Legacy Survey Of Space And Time

An Unidentified Absorption Feature At 5.11 μm On The Surface Of Titan And Pluto From JWST Spectroscopy

PJ Harvey Announces New Song “Voyager”

Fifty Years after Viking: The Promise of Solar System Microbiology and Microbial Ecology

Characterising Transiting Exoplanets At Long Orbital Period: Lessons Learned For PLATO From 10 Years Of Monitoring The HIP41378 System

Implications Of Self-consistent H2O Ice Optical Constants On Radiative Transfer Models Of Disks

The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c