Astrochemistry

[physics.geo-ph]. The weathering of iron-rich phases within meteorites is a multi-stage process that significantly alters the microstructure and chemical composition based both on the environmental condition at the location of […]

Overview of the ML-DH framework. Top: Training stage, using DFT energies, forces, and dipoles to train the NNFF and EPNN. Bottom: Prediction stage, yielding IR spectra via NNFF optimization, normal mode analysis, and EPNN dipole derivatives.-- [astro-ph.GA]

A Machine-learning-driven Dataset Of 144,111 Polycyclic Aromatic Hydrocarbon Infrared Spectra For Interpreting Aromatic Infrared Bands

[astro-ph.GA] The interpretation of interstellar aromatic infrared bands (AIBs) relies on reference spectral libraries, but the chemical space covered by existing databases remains incomplete relative to the vast structural diversity […]

Current ALMA can detect the rich chemistry within the snowline around higher-mass stars, with an example spectrum shown in the top panel. For Sun-like stars, mapping across the CO snowline only ( > ∼ 10 au) is currently possible, which corresponds to the giant planet formation zone. The step changes in spatial resolution and sensitivity provided by ALMA2040 will allow us to detect and map the composition of terrestrial-planet-building material around Sun-like stars. Data from Qi et al. (2013), Andrews et al. (2016), and Booth et al. (2024a). -- [astro-ph.IM]

Chemistry On Solar System Scales

[astro-ph.IM]. The initial chemical composition of planets, primitive bodies in our solar system, and exoplanets is ultimately set by their nascent protoplanetary disks.

(Left) The N2H +/HCN ratio toward the central region of M83 shown in the color scale. The black contours show 3-mm continuum intensities with 0.5 mJy beam−1 increments. The beam size is shown at the bottom left corner. (Right) The same figure as Figure 2(a), but including data points from the galactic center region. The grey dashed lines have slopes of 1, and show the lines of constant N2H +/HCN ratios. -- [astro-ph.GA]

ALMA Observations Towards M83 Reveal N2H+ Tracing Dense Gas

[astro-ph.GA] Galactic observations have shown that N2H+ intensities preferentially trace star-forming dense molecular gas compared with HCN or HCO+, which are conventionally used as dense-gas tracers in extragalactic studies.

ZTF image sequences of 3I before and after perihelion. Panel (a) shows the pre-perihelion images, and panel (b) shows the post-perihelion images. The observation time is marked in each panel. The white scale bars indicate angular distances of 30′′ in panel (a) and 60′′ in panel (b). All images are oriented with north up and east to the left. The cyan arrows labeled ⊙, −⊙, and −v indicate the projected solar, anti-solar, and anti-velocity directions, respectively, and the cyan cross marks the photometric center. -- [astro-ph.EP]

Comets and Asteroids

Dust Activity Evolution and Constraints on Icy Grains in the Interstellar Comet 3I/ATLAS

[astro-ph.EP] We present Zwicky Transient Facility observations of the interstellar comet 3I/ATLAS to characterize its dust-activity evolution before and after perihelion.

Sample Return

NASA Curation Community Conversation Webinar

[NASA] On November 2, 2026, at 2 PM Eastern Time, NASA’s Chief Scientist for Astromaterials Curation within the Science Mission Directorate and NASA’s Astromaterials Curator will host a webinar to […]

Integrated intensity maps of the 1.7 mm continuum, 183 GHz water line, and three methanol lines in the HD 100546 (top row) and IRS 48 (bottom row) disks. White contours highlight the inner dust ring of HD 100546 and the asymmetric mm-crescent of IRS 48 from their continuum maps, pink contours show 3, 4, and 5σ levels. The white ellipse in the bottom left of each panel shows the beam.-- [astro-ph.EP]

An ALMA View On Molecular Complexity: Water, Methanol, And Methyl Formate In The HD 100546 And IRS 48 Disks

[astro-ph.EP] Water and methanol are the fundamental constituents of interstellar and cometary ices: understanding their abundances in disks is therefore of high importance to reveal how this ice reservoir evolves […]

SVUV-PI-ReToF-MS data during the TPD phase of irradiated CH4–O2 ice. Data were recorded at the photon energy of 10.49 eV. The irradiated ices were prepared under the exposure of 5 keV electrons of 50 nA for 30 minutes. -- Nature Communications Chemistry

Experimental Astrochemistry And Machine Learning Unravel The Formation Of Oxygen-bearing Organic Molecules In Extraterrestrial Ices

[Nature Communications Chemistry] Oxygen-bearing organic molecules, including aldehydes, alcohols, and peroxides, serve as key precursors to complex organics in extraterrestrial environments. Their non-equilibrium formation mechanisms critically constrain the molecular complexity […]

From interstellar molecules to biomolecules. [astro-ph.IM]

Frontiers Of Chemical Complexity In The Interstellar Medium: Unveiling The Cosmic Origins Of life