On December 18th, skywatchers will have the opportunity to observe a rare event: the closest approach of interstellar comet 3I/ATLAS to Earth. The Virtual Telescope Project will broadcast a free livestream starting at 11 p.m. EST (0400 GMT on December 19th), providing real-time telescope views from their robotic observatories in Italy, weather permitting.
What Makes This Comet Special?
Comet 3I/ATLAS, discovered in July 2025 by the ATLAS survey system, is only the third confirmed interstellar object to visit our solar system. The first two were 1I/’Oumuamua (2017) and 2I/Borisov (2019). These comets come from outside our solar system, offering astronomers a unique chance to study material from other planetary systems.
This is valuable because: interstellar comets can reveal clues about how planets form around other stars. Their composition and behavior are different from objects native to our solar system, providing a comparative data point for planetary science.
Viewing Details
The comet will reach its closest point to Earth at 1 a.m. EST (0600 GMT) on December 19th, at a distance of roughly 168 million miles (270 million kilometers) – nearly twice the Earth-Sun distance.
It won’t be visible with the naked eye. Even small telescopes will struggle to resolve it. Observers with larger (8-inch or greater) backyard telescopes may catch a faint, fuzzy light under dark skies. For most, the livestream is the most accessible way to observe this event.
The Virtual Telescope Project livestream will share telescope views of the comet in real time, allowing a global audience to experience this cosmic flyby without specialized equipment.
This comet is a rare opportunity to study material from another star system directly, helping scientists understand planetary formation beyond our own solar neighborhood. It’s a reminder that our solar system is just one of many in the vast universe.
