Comets and Asteroids – Page 5 – My WordPress Site

Examples of metabolic networks (gray nodes and edges) and seed sets (blue circles).

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Impact events, Meteorites & Asteroids, Origin & Evolution of Life, Panspermia

Potential Metabolic Viability On Asteroid Chemistry

by Keith CowingJanuary 26, 2026January 26, 2026

Representative SWAN full-sky Lyman-α map (2025 Nov 13), showing the simultaneous detection of comet C/2025 K1 (ATLAS) and numerous UV-bright stars. The zoomed inset displays the differential image centered on 3I/ATLAS, illustrating its stellar-like appearance after the pipeline subtracts the IPH background and faint stellar sources. Residual artifacts remain for luminous stars. -- astro-ph.EP

Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar

Perihelion Asymmetry In The Water Production Rate Of Tthe Interstellar Object 3I/ATLAS

by Keith CowingJanuary 26, 2026January 26, 2026

Spectroscopic observations of β Pic obtained on April 29, 2025. The HARPS spectrum is not flux-calibrated and was simply renormalized to a flux level similar to that of the STIS data. Numerous saturated absorption lines are visible in the STIS and HARPS spectra, attributed to Si ii, C i, Al ii, Fe ii, Mg ii and Ca ii. The HST spectra are consistent with a stellar model from the PHOENIX library (thick grey line, Husser et al. 2013) at Teff = 8000 K (see Sect. 4.1). -- astro-ph.EP

Beta Pictoris, Comets and Asteroids, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy

Transit Distances And Composition Of Low-velocity Exocomets In The β Pictoris System

by Keith CowingJanuary 25, 2026January 25, 2026

Structure of the nomenclature with each of the elements highlighted with a description. -- astro-ph.EP

Comets and Asteroids, Exoplanets, -moons, -comets, Nomenclature, Systematics, Natural History, Stellar Cartography

A Nomenclature For Individual Exocomets

by Keith CowingJanuary 24, 2026January 24, 2026

(A) Pre and post irradiation spectra of the fiducial 10 K 2:1 benzene:ozone experiment. (B) Spectra of pure phenol ice at 10 K, (C) Spectra of a ∼ 30:1 benzene:phenol mixture at 10 K (D) Spectra of a benzene-oxide/oxepine mixture at 10 K reproduced with permission from Schleif et al. (2020). Optimized geometries representative of phenol, benzene oxide and oxepine are obtained using Gaussian 16 suite of software and are shown for reference in the corresponding panel. For clarity, only relevant spectral region are shown, full spectral data are available for download at 10.5281/zenodo.17216222 and 10.5281/zenodo.17216256 -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar

Functionalization Of Benzene Ices by Atomic Oxygen

by Keith CowingJanuary 20, 2026January 20, 2026

Polarization degree (Pr) and polarization position angle (θr) of 3I/ATLAS as a function of phase angle, measured in five bands (RC, IC, J, H, and Ks). Colored symbols denote our visible and near-infrared imaging polarimetric data obtained with different instruments, while orange symbols show previously published measurements of 3I/ATLAS (Z. Gray et al. 2025; M. Zheltobryukhov et al. 2025). Gray symbols represent polarimetric measurements of Solar System comets compiled in the Database of Comet Polarimetry (DBCP; N. Kiselev et al. 2017), and the pink triangles indicate the PPC of the interstellar comet 2I/Borisov (S. Bagnulo et al. 2021). The dashed curves show the best-fit linear–exponential models (Equation 1) to our data. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy

Dust Properties of the Interstellar Object 3I/ATLAS Revealed by Optical and Near-Infrared Polarimetry

by Keith CowingJanuary 15, 2026January 15, 2026

Distribution of hits (circles) and events (stars) over frequency and drift rate. The marker size gives the S/N. The gray-shaded regions show ranges not sampled, including narrow notch filter regions in the L and S bands. The color-shaded regions give the range of drift rates expected from Earth’s orbital motion and rotational motion and 3I/ATLAS’s rotation at each of the four observing bands. These regions do not perfectly align between bands due to 3I/ATLAS’s radial acceleration changing during overhead time between observations. No events lie in the expected drift rate regions. -- astro-ph.IM

Astronomy & Telescopes, Comets and Asteroids, Imaging & Spectroscopy, Intelligence & Language, Interstellar, SETI & Technosignatures

Breakthrough Listen Observations Of 3I/ATLAS With The Green Bank Telescope at 1-12 GHz

by Keith CowingDecember 31, 2025December 31, 2025

Comet Interceptor -- ESA

Astrogeology, Comets and Asteroids, Icy Worlds, Missions & Hardware

Considerations On The Process Of Target Selection For The Comet Interceptor Mission

by Keith CowingDecember 30, 2025December 30, 2025

Combined white light image of 3I/ATLAS, created by median stacking white light images produced by collapsing in wavelength individual data cubes. The field of view displayed is 40 arcsec x 40 arcsec . Intensities are in units of 10-20 ergs−1 cm−2. Countours are over plotted. Snapshot of a new interstellar comet: 3I/ATLAS has a red and featureless spectrum, MRAS

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Interstellar

University Of Canterbury Team Led Study Of Interstellar Comet 3I/ATLAS

by Keith CowingDecember 30, 2025December 30, 2025

A)–(D). Spectrally integrated flux maps for HCN, CO, CH3OH, and CS in K2. Contour intervals in each map are given in multiples of the rms noise. The rms noise (σ, mJy beam−1 km s−1 ) is indicated in the upper left corner of each panel. Sizes and orientations of the synthesized beam (Table 1) are indicated in the lower left corner of each panel. The comet’s observer-centered illumination (ϕ ∼ 25◦ ), as well as the direction of the Sun and dust trail, are indicated in the lower right. The black cross indicates the position of the peak continuum flux. A spectrum extracted from a 10′′ diameter aperture centered on the nucleus is shown in the upper right. Contours are in 10σ increments for HCN and 5σ increments for CO, CH3OH, and CS. -- astro-ph.EP

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy

The Evolution in Coma Molecular Composition of Comet C/2017 K2 (PanSTARRS) Across the H2O Sublimation Zone: ALMA Imaging of an H2O-Dominated Coma

by Keith CowingDecember 29, 2025December 29, 2025