Astronomers have determined that the interstellar comet 3I/ATLAS [1] may be up to 12 billion years old [2].
The discovery provides a rare glimpse into the chemical composition of the early universe. Because the comet formed in a colder, more intense region of the galaxy before the birth of the Sun, it serves as a prehistoric record of galactic evolution.
Researchers utilized data from the James Webb Space Telescope and the ALMA observatory in Chile to analyze the object. The comet traversed the inner Solar System in 2025 [3]. Chemical and isotopic signatures indicate the object originated in a region of space significantly older than our own planetary neighborhood [4].
While some early speculation suggested the comet could be an alien spacecraft, recent findings contradict those theories. Researchers at the SETI Institute and other astronomers said the object looks completely natural. The data shows no evidence of alien technology [5].
The analysis, published between May and June 2026, confirms the comet is an interstellar visitor rather than a native object. Its extreme age suggests it has traveled across vast distances of the galaxy before entering the Solar System [2, 4].
Scientists used the ALMA radio telescope array to supplement the infrared observations from the James Webb Space Telescope. This multi-instrument approach allowed the team to verify the comet's isotopic makeup, a key factor in determining its age [1, 2].
“The comet may be up to 12 billion years old.”
The confirmation that 3I/ATLAS is a natural object from the early universe allows astronomers to study materials that predated the Sun. By analyzing these ancient isotopic signatures, scientists can better understand the conditions of the galaxy 12 billion years ago, effectively using the comet as a time capsule to study the chemical precursors of planetary systems.
