On Friday, the interstellar comet 3I/ATLAS makes its nearest approach to Earth, bringing the captivating alien visitor closer than ever before its exit from our Solar System.
The comet, first spotted in July by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, has become one of the biggest astronomy sensations in recent memory, with its odd behavior spawning theories—and controversies—about the possibility of alien technologies.
Part of what makes the comet so fascinating is that 3I/ATLAS is only the third confirmed interstellar visitor ever detected passing through our solar system, and its recent visit signals the likelihood of similar observations made possible in the years ahead by the ever-growing number of advanced ground- and space-based observatories.
With the comet’s closest approach to Earth happening right now, many are wondering how they can catch a final glimpse of 3I/ATLAS before it resumes its journey through interstellar space. Fortunately, there are several ways you can keep up to speed on one of the fastest, oldest, and arguably most intriguing comets astronomers have ever seen.
Keeping Up with 3I/ATLAS During Its Flyby
NASA is keeping an eye on 3I/ATLAS with its Eyes on the Solar System page, which offers one way to track 3I/ATLAS during its closest approach on Friday.
Beyond the American Space Agency, the Comet Observation Database (COBS) is also monitoring 3I/ATLAS, as is the Virtual Telescope Project (although due to weather conditions, its planned observations for Friday, December 19th, have been postponed until 11 PM ET on Friday (see below).
What to Know About 3I/ATLAS During Its Closest Approach
Due to several unusual features of 3I/ATLAS, speculations about the comet—including whether it might represent alien technology, or even impact the Earth or pose any threat—have proliferated online for several months.
NASA officials have stressed that although its approach on Friday brings 3I/ATLAS closer to our planet than at any other time during its visit to our solar system, the interstellar comet will at no time be close enough to pose any risk from possible impact.
Advanced—and very reliable—calculations about the comet’s trajectory have never indicated any kind of impact risk, although the comet’s sudden appearance and unusual characteristics have made it an ideal target for tracking efforts that could inform future efforts to detect and track any space objects that could present a threat potential.
And while speculation about alien technology remains popular regarding 3I/ATLAS, astronomers have detected no obvious signatures or other indications that suggest 3I/ATLAS is anything but a natural comet. While it does exhibit several unusual qualities, these are to be expected from a large object that originated in another star system, and which has spent the last several eons drifting through the frigid cold of interstellar space.
How to Spot 3I/ATLAS Yourself
For much of late 2025, the comet has been a faint morning object for Northern Hemisphere observers, drifting through the constellation Virgo and later into Leo. The comet is too faint to be perceptible with the naked eye, although viewers armed with even a small telescope or a decent pair of binoculars may be able to spot it as an extremely faint smudge of light in the pre-dawn sky near Regulus, the brightest star in the constellation Leo.
What’s Next for 3I/ATLAS?
Astronomers currently believe 3I/ATLAS may be among the oldest comets ever observed, potentially even predating the formation of our solar system. The more we learn about objects like 3I/ATLAS, the more we learn about the raw materials that compose planetary systems throughout our galaxy.
Following its nearest approach on Friday, 3I/ATLAS heads off next toward Jupiter and Saturn, which it will visit next year before it leaves our solar system entirely.
Fortunately, long after this interstellar visitor fades from view, the wealth of data astronomers have gathered during its fleeting visit will likely be more than enough to keep scientists busy for decades to come, as we continue to expand our understanding of what populates the cosmos far beyond our stellar neighborhood.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.