Science and climate correspondent<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n A mystery interstellar object spotted last week by astronomers could be the oldest comet ever seen, according to scientists.<\/p>\n Named 3I\/Atlas, it may be three billion years older than our own solar system, suggests the team from Oxford university.<\/p>\n It is only the third time we have detected an object that has come from beyond our solar system.<\/p>\n The preliminary findings were presented on Friday at the national meeting of the UK’s Royal Astronomical Society in Durham.<\/p>\n<\/div>\n “We’re all very excited by 3I\/Atlas,” University of Oxford astronomer Matthew Hopkins told BBC News. <\/p>\n “I’ve just finished my PhD where I spent four years predicting the discovery of [more] interstellar objects, and then for the first time in my studies, we found one,” he said. <\/p>\n Based on the object’s speed, Mr Hopkins says it could be more than seven billion years old, and it may be the most remarkable interstellar visitor yet.<\/p>\n 3I\/Atlas was first spotted on 1 July 2025 by the Atlas survey telescope in Chile, when it was about 670 million km from the Sun.<\/p>\n It is currently visible only with very large telescopes, and it is about the distance of Jupiter from Earth.<\/p>\n Since then astronomers around the world have been racing to identify its path and discover more details about it.<\/p>\n Mr Hopkins believes it originated in the Milky Way’s “thick disk”. This is a group of ancient stars that orbit above and below the area where the Sun and most stars are located.<\/p>\n The top view of the Milky Way, below, gives a sense of the object’s path around our galaxy. The estimated orbits of 3I\/Atlas are in red and those of our Sun are in yellow. <\/p>\n<\/div>\n The team believe that because 3I\/Atlas probably formed around an old star, it is made up of a lot of water ice.<\/p>\n That means that as it approaches the Sun later this year, the energy from the Sun will heat the object’s surface, leading to blazes of vapour and dust.<\/p>\n That could create a glowing tail.<\/p>\n The researchers made their findings using a model developed by Mr Hopkins.<\/p>\n “This is an object from a part of the galaxy we’ve never seen up close before,” said Prof Chris Lintott, co-author of the study.<\/p>\n “We think there’s a two-thirds chance this comet is older than the solar system, and that it’s been drifting through interstellar space ever since.”<\/p>\n Interstellar objects form around other stars, at the start of those stars’ lives, explains Mr Hopkins.<\/p>\n “This connection back to their parent stars means that we can look at the stellar population of the Milky Way,” he adds.<\/p>\n Later this year, 3I\/Atlas should be visible from Earth using amateur telescopes.<\/p>\n Before 3I\/Atlas soared into view, just two others had been seen. One was called 1I\/’Oumuamua, found in 2017 and another called 2I\/Borisov, discovered in 2019.<\/p>\n Astronomers globally are currently gearing up to start using a new, very powerful telescope in Chile, called the Vera C Rubin. <\/p>\n When it starts fully surveying the southern night sky later this year, scientists expect that it could discover between five and 50 new interstellar objects.<\/p>\n<\/div>\n<\/div>\n![\"ESO\/O.](\"https:\/\/ichef.bbci.co.uk\/news\/480\/cpsprodpb\/2d70\/live\/572ba820-5e32-11f0-960d-e9f1088a89fe.jpg.webp\")
ESO\/O. Hainaut<\/span><\/div>\n<\/div>\n![](\"https:\/\/static.files.bbci.co.uk\/bbcdotcom\/web\/20250701-150711-e3d94715db-web-2.24.1-1\/grey-placeholder.png\")
![\"Matthew](\"https:\/\/ichef.bbci.co.uk\/news\/480\/cpsprodpb\/6a3c\/live\/78c4b920-5e48-11f0-b5c5-012c5796682d.jpg.webp\")
Matthew Hopkins<\/span><\/div>\n<\/div>\n