Interstellar Comet 3I/ATLAS Surges Into View—When and Where to See the Rare Cosmic Visitor

Astronomers are buzzing about a rare celestial visitor: interstellar comet 3I/ATLAS, officially cataloged as C/2025 N1. Discovered on 1 July 2025 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Hawai‘i, the object is only the third confirmed comet known to have arrived from outside our solar system, after ‘Oumuamua in 2017 and 2I/Borisov in 2019. Fresh Hubble images released this week show 3I/ATLAS as a compact dusty nucleus trailed by a gossamer-thin tail some 178 million miles (286 million km) from Earth. The NASA/ESA photos confirm that the comet remains intact and is brightening as it approaches perihelion—its closest point to the Sun—on 14 January 2026 at 1.36 AU, just beyond Mars’ orbit. Why 3I/ATLAS matters • Pristine interstellar ice: Spectra from NASA’s Infrared Telescope Facility hint at unusually volatile-rich ices, untouched since the comet left its natal star system millions of years ago. • Possible cryovolcanic activity: Hubble photometry reveals episodic brightenings that may signal “ice-volcano” jets blasting dust and gas—behavior never conclusively observed on an interstellar object before. • Trajectory clues: Its hyperbolic excess velocity of 26 km/s indicates an origin in the far reaches of the Carina-Columba stellar association, offering a data point for models of planet-forming disks beyond the Sun. How to see it The comet is racing northward through the constellation Eridanus and will skim the ecliptic in early January. Peak visibility for backyard telescopes comes around 27 December, when 3I/ATLAS climbs above 40° elevation for mid-northern observers at a predicted magnitude of 11.8. Use a 6-inch (150 mm) scope and a medium-power eyepiece; long-exposure astro-photography will reveal the faint ~4-arcminute tail. Looking ahead NASA’s James Webb Space Telescope has scheduled mid-infrared observations for 8 January to dissect the comet’s dust composition, while the European Space Agency’s Comet Interceptor mission team is evaluating a potential flyby plan should launch delays shorten their travel time. Amateurs can contribute by uploading photometry to the Minor Planet Center; coordinated light-curve analysis will refine models of the nucleus’ spin state. Bottom line Interstellar comet 3I/ATLAS offers an unparalleled chance to sample material from another solar system without leaving home. Mark your skycharts now: the next such visitor may be decades away, but 3I/ATLAS is lighting up December’s night sky right on schedule.