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.

A mystery interstellar object discovered last week is likely to be the oldest comet ever seen—possibly predating our solar system by more than 3 billion years, researchers say.

A mystery interstellar object spotted last week by astronomers could be the oldest comet ever seen, according to scientists. Named 3I/Atlas, it may be three billion years older than our own solar system, suggests the team from Oxford university.