[SwRI] A Southwest Research Institute-led study used NASA’s James Webb Space Telescope to examine ice grains streaming from interstellar comet 3I/ATLAS, just the third object from beyond our solar system […]
Comet
![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]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Dust-Activity.png?resize=1200%2C719&ssl=1)
Posted inComets 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.
![Relative emissivity spectrum of 2P/Encke’s nucleus obtained by the COMICS observations, in comparison with that of 460P/PanSTARRS (T. Ootsubo et al. 2021). The spectrum of 460P/PanSTARRS (in grey) is shifted by 0.1 for the readability. The grey hatched area is the wavelength region influenced by the telluric ozone absorption. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Photometric.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
Photometric and Spectroscopic Observations of Comet 2P/Encke’s Nucleus in the Mid-Infrared Wavelength Region
[astro-ph.EP] We observed comet 2P/Encke with the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on the Subaru telescope on UT 2003 November 12.3, when the comet was at heliocentric and geocentric […]
Posted inAstrogeology
A JWST Study Oof Stardust. II. Polycyclic Aromatic Hydrocarbons in Comet 81P/Wild 2 And Implications For Primitive Solar System Carbon
[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 […]
![Initial 𝑎c–𝑒c distribution of the 32,000 comets used in each end-to-end calculation. Dashed lines mark the semimajor axes of P7 and P8. The circular and eccentric planet calculations use identical comet initial states.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Planetary.png?resize=1200%2C604&ssl=1)
Posted inComets and Asteroids
Planetary Eccentricity Enhances Inward Comet Transport But Suppresses Gentle Impacts
[astro-ph.EP] Comets can supply volatile and prebiotic material to rocky planets, but survival of fragile molecules depends on atmospheric entry and impact. Compact planet chains can transfer comets inward at […]
![Median protoplanetary disk composition predicted by the chemical model at different metallicities [Fe/H]. LEFT: Median overall composition. RIGHT: Median refractory composition. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/On-the.png?resize=1200%2C719&ssl=1)
Posted inInterstellar
On The Compositions Of Interstellar Objects
[astro-ph.EP] As physical samples of distant planetary systems, the compositions of interstellar objects (ISOs) should correlate with the properties of their diverse parent stars.
Posted inAstrochemistry
Nonequilibrium Formation of C4 Carbonyls in Interstellar Ices Linked to Amino Acids
[ACS Central Science] Complex organic molecules in interstellar ices and carbonaceous asteroids record key steps in the chemical evolution toward life, yet the origin of branched carbonyl compounds a fundamental […]
Posted inComets and Asteroids
Multiband Color Monitoring of 3I/ATLAS Through Ground-Based Relay Observations
[astro-ph.EP] We present multiband, long-baseline photometric observations of interstellar comet 3I throughout its 2025–2026 apparition using coordinated ground-based global relay observations.
![Sky-coverage of the four surveys utilized in this study, with celestial coordinates displayed. It depicts three consecutive observation sectors of TESS, labeled as i−1, i, and i+1. Each of the four TESS cameras is represented by a different color. The beginning of each sector is marked in gray at an ecliptic latitude of 6 deg. The green area indicates the observing region of the fourth camera, which begins at an ecliptic latitude of 78 deg and encompasses the entire ecliptic pole. The magenta, yellow, and grey areas depict the typical 15-day observation coverage of LSST, Pan-STARRS, and ATLAS-W68, respectively. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/1IOumuamua.png?resize=1200%2C717&ssl=1)
Posted inInterstellar
1I/’Oumuamua-like Objects’s SFDs With Older, Current And Future Surveys
[astro-ph.EP] Interstellar Objects (ISOs) may provide direct evidence of planetesimals ejected from early-stage solar systems. Studying these objects and predicting their detection through various surveys is vital for enhancing our […]
![Orbit of 3I/ATLAS showing the 17 UVES/VLT observing epochs. Open and filled circles represent pre- and post-perihelion observations, respectively. Planet positions with filled circles are shown for the date of perihelion. The open diamond marks Earth’s position at the discovery of 3I/ATLAS, while the open circles along Earth’s orbit indicate its position at each observing epoch. [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/High-resolution.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
High-resolution Optical Spectroscopy Reveals The Distinctive Volatile Composition Of The Interstellar Comet 3I/ATLAS
[astro-ph.EP] Comets preserve volatile material from the early stages of planetary-system formation. The discovery of the interstellar comet 3I/ATLAS enables a direct comparison between a comet formed around another star […]