China’s Tianwen-1 Mars orbiter successfully imaged the third interstellar object, 3I/ATLAS, during its close encounter with Mars using the onboard HiRIC CMOS camera. This is China’s first deep-space observation of […]
3I/ATLAS
A Direct View of the Chemical Properties of Water from Another Planetary System: Water D/H in 3I/ATLAS
All detected water reservoirs in the solar system exhibit a deuterium enrichment that links back to the physical environment at the time of stellar birth.
Time-Domain Photometry and Activity Evolution of Interstellar Comet 3I/ATLAS with BHTOM
Time-domain photometric monitoring is essential for characterizing cometary evolution, particularly for rare interstellar objects with limited observing opportunities.
ALMA Detects Extremely Abundant Alcohol in Interstellar Comet 3I/ATLAS
Comet 3I/ATLAS continues to make astonishing headlines, thanks to new findings from astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), of which the U.S. National Science Foundation National Radio Astronomy […]
HATPI Pre-Perihelion Time-series Photometry of the Interstellar Comet 3I/ATLAS
HATPI is a recently commissioned time-domain facility at Las Campanas Observatory, Chile, that uses 64 wide-angle, 9.6 cm diameter lenses and back-illuminated CCDs, yielding a mosaic field-of-view of 7,100 square […]
Post-Perihelion Integral Field Spectroscopy Of The Interstellar Comet 3I/ATLAS
The environs of other stellar systems may be directly probed by analyzing the cometary activity of interstellar objects. The recently discovered interstellar object 3I/ATLAS was the subject of an intensive […]
Perihelion Asymmetry In The Water Production Rate Of Tthe Interstellar Object 3I/ATLAS
3I/ATLAS is an interstellar object whose activity provides critical insights into its composition and origin. However, due to its orbital geometry, the object is too close to the Sun near […]
SPHEREx Re-Observation of Interstellar Object 3I/ATLAS in December 2025: Detection of Increased Post-Perihelion Activity, Refractory Coma Dust, and New Coma Gas Species
In December-2025, the NASA SPHEREx spacecraft re-observed ISO 3I/ATLAS post-perihelion, finding a much more active object compared to August-2025 SPHEREx pre-perihelion observations, with marked evidence for development into an cometary […]
Dust Properties of the Interstellar Object 3I/ATLAS Revealed by Optical and Near-Infrared Polarimetry
We present independent polarimetric observations of the interstellar object 3I/ATLAS, including the first near-infrared polarimetric measurements. Using imaging polarimeters, we measured the degree of linear polarization from the visible RC […]
Breakthrough Listen Observations Of 3I/ATLAS With The Green Bank Telescope at 1-12 GHz
3I/ATLAS (also designated C/2025 N1 (ATLAS) and, formerly, A11pl3Z) is the third interstellar object (ISO), following 1I/‘Oumuamua and 2I/Borisov, to be discovered during a passage through the Solar System. The […]
