[astro-ph.EP] We present 14 optical imaging and eight optical spectroscopic epochs of interstellar comet 3I/ATLAS from Keck/LRIS and Gemini/GMOS, two near-infrared (NIR) imaging epochs from Keck/MOSFIRE, and four NIR spectroscopic […]
3I/ATLAS
Posted inAstrogeology
JWST/MIRI Observations of Amorphous Silicates In Interstellar Comet 3I/ATLAS
[astro-ph.EP] We present JWST/MIRI Low Resolution Spectroscopy (LRS) of 3I/ATLAS obtained post-perihelion at a heliocentric distance of 2.21 au.
Posted inComets and Asteroids
Webb Space Telescope Used To Compare Interstellar Comet 3I/ATLAS With Icy Bodies In Our Solar System
[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 […]
Posted inInterstellar
Assessment Of The Mass Loss And Radius Change Of 3I/ATLAS Based On Observed Production Rates
[astro-ph.EP] Formed from the debris of planet formation, interstellar comets provide invaluable insights into the chemical compositions of planetary systems outside of our Solar System.
![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.
![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 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 […]
![Temporal evolution of selected species and D/H ratios during the cloud (top panels) and core stages (lower panels). Panels (a) and (e) show the abundances of selected species during the cloud and core stages, respectively. Solid, dashed, and dotted lines denote models with Z = 1, 0.5, and 0.2, respectively. The remaining panels show the temporal evolution of the D/H ratios and the H2 OPR for Z = 1 (b, f), Z = 0.5 (c, g), and Z = 0.2 (d, h). In all panels, time is normalized by τfreeze for the corresponding density and metallicity. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/High-water.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry
High Water D/H Ratio of the Interstellar object 3I/ATLAS is Consistent With a Low-metallicity Origin
[astro-ph.EP] Recent JWST observations have revealed unusually high 12C/13C ratios in carbon-bearing molecules of the interstellar object 3I/ATLAS, consistent with formation in a lower-metallicity environment than the present-day local interstellar […]
Posted inUncategorized
Multi-Wavelength Post-Perihelion Polarimetry of Interstellar Comet 3I/ATLAS
[astro-ph.EP] We present new post-perihelion polarimetric observations of the third discovered interstellar object, 3I/ATLAS (C/2025 N1; hereafter 3I), obtained using FORS2 at the Very Large Telescope, ALFOSC at the Nordic […]