Interstellar object could be oldest known comet

Astronomers have stumbled upon a fascinating object called 3I/Atlas, which might just be the oldest comet we've ever spotted. Researchers from Oxford University believe it could be a staggering three billion years older than our solar system. This discovery marks only the third interstellar object ever found.

The initial findings were presented at a gathering of the UK's Royal Astronomical Society. Matthew Hopkins, an astronomer at Oxford, couldn't hide his excitement about this groundbreaking discovery, highlighting that it represents a major milestone after years of predictions made during his PhD research. Based on its speed, 3I/Atlas could be over seven billion years old, making it an extraordinary find.

3I/Atlas was first observed on July 1, 2025, by the Atlas telescope in Chile when it was about 670 million kilometers away from the Sun, currently at a distance comparable to that of Jupiter from Earth. Astronomers are hard at work analyzing its trajectory and gathering more details about it. Hopkins speculates that this object likely hails from the "thick disk" of the Milky Way, an area filled with ancient stars.

The researchers think that 3I/Atlas probably holds a significant amount of water ice, which will turn into a glowing tail as it approaches the Sun later this year. This idea is based on a model developed by Hopkins.

Prof. Chris Lintott, a co-author of the study, pointed out that this is a unique chance to observe a part of the galaxy that has never been seen up close. There's a two-thirds chance that the comet is older than the solar system and has been journeying through interstellar space since it formed around an ancient star.

Later this year, 3I/Atlas is expected to be visible from Earth with amateur telescopes. Before this, only two similar objects had been recorded: 1I/‘Oumuamua in 2017 and 2I/Borisov in 2019. Astronomers are gearing up to use a powerful new telescope in Chile, which is anticipated to discover between five and 50 more interstellar objects when it starts surveying the southern night sky.

Reference

by Georgina Rannard. Mystery interstellar object could be oldest known comet

bbc.co.uk Available at- https://www.bbc.co.uk/news/articles/cx23g5jpj9go

(Assessed: 17th July 2025)