The Chemistry of Interstellar Comet 3I/ATLAS Is Unlike Anything We've Ever Seen

Interstellar comet that zoomed past Earth could be oldest and coldest object ever seen in solar system, astronomers say

Exactly where the comet 3I/ATLAS came from within the Milky Way remains a mystery.

Interstellar comet likely far older than Solar System: astronomers

PARIS, France — An interstellar comet that blazed past the Sun last year could be nearly three times older than our Solar System and is unlike anything ever before seen in our cosmic backyard, astronomers said Monday.

The Chemistry of Interstellar Comet 3I/ATLAS Is Unlike Anything We've Ever Seen

All signs were already indicating that interstellar comet 3I/ATLAS was unlike anything we'd ever seen.

Interstellar Comet 3I/ATLAS is almost as old as the universe itself

The evidence is mounting: this interstellar visitor is even older and weirder than anyone thought

In July 2025 astronomers spotted only the third object ever confirmed to come from beyond our Solar System — a comet called 3I/ATLAS that may be 12 billion years old, older than the Sun itself, passing through once at a speed too high ever to be captured, and then gone back into interstellar space forever.

Almost a year after its discovery, the interstellar object known as 3I/ATLAS hit the headlines again. Researchers announced in early 2026 that the object may be 12 billion years old, potentially making it older than our Sun and one of the oldest known comets ever observed by humanity. And it is just the latest in a long string of interesting turns that make 3I/ATLAS one of the most curious space objects we’ve ever seen. Space Shuttle at Smithson…