The recently discovered interstellar visitor 3I/ATLAS may be one of the oldest comets ever seen by humanity.
The object was already exciting to astronomers as only the third space object seen entering the solar system from beyond its limits, the other two being 1I/’Oumuamua seen in 2017 and 2I/Borisov detected in 2019.
However, new research has shown this potentially “water ice-rich” visitor could be even more extraordinary than initially believed. 3I/ATLAS could be around 3 billion years older than our 4.5 billion-year-old solar system and thus any comet ever before observed.
University of Oxford astronomer Matthew Hopkins is part of a team of scientists that think 3I/ATLAS, discovered on July 1, 2025 by the ATLAS survey telescope, is around 7 billion years old.
“All non-interstellar comets, such as Halley’s comet, formed at the same time as our solar system, so they are up to 4.5 billion years old,” Hopkins said in a statement. “But interstellar visitors have the potential to be far older, and of those known about so far, our statistical method suggests that 3I/ATLAS is very likely to be the oldest comet we have ever seen.”
Hellbound and Down 