Astronomers have identified a rare interstellar object, dubbed 3I/Atlas, that could be the oldest comet ever observed, possibly predating our solar system by three billion years, according to researchers from the University of Oxford.

This discovery marks just the third confirmed instance of an object arriving from beyond our solar system, following the groundbreaking sightings of 1I/‘Oumuamua in 2017 and 2I/Borisov in 2019.

The research team shared their early findings during the Royal Astronomical Society’s national meeting in Durham. Leading the study, astronomer Matthew Hopkins expressed his excitement: “I spent four years of my PhD predicting this exact kind of discovery — and now it’s finally happened.”

3I/Atlas was detected on 1 July 2025 by the Atlas survey telescope in Chile. At the time, it was located approximately 670 million kilometers from the Sun — about the same distance as Jupiter. Despite being faint and currently visible only through powerful telescopes, it’s quickly capturing the attention of astronomers worldwide.

Hopkins and his colleagues estimate that based on its velocity and trajectory, 3I/Atlas could be more than seven billion years old, making it a time capsule from a distant corner of the galaxy.

The team believes the object originated in the Milky Way’s thick disk — a lesser-known region composed of ancient stars that orbit above and below the galaxy’s primary disk, where the Sun resides. Because of its likely origin around an ancient star, scientists think the object is rich in water ice, setting the stage for a potential spectacle later this year.

“As 3I/Atlas approaches the Sun, we expect solar radiation to heat its surface, releasing plumes of vapor and dust and possibly forming a glowing comet-like tail,” Hopkins explained.

Using a model developed specifically for this study, the team traced the likely orbit of 3I/Atlas through the galaxy, offering unprecedented insight into objects from ancient star systems.

“This is the closest look we’ve had at matter from such a distant and old part of the galaxy,” said Professor Chris Lintott, co-author of the study. “We estimate there’s a two-in-three chance that 3I/Atlas is older than the solar system itself.”

The object’s interstellar nature means it was likely formed during the birth of another star system, making it a messenger from another era and place in the Milky Way.

Later this year, 3I/Atlas could become visible to amateur astronomers with mid-sized telescopes as it draws closer to the Sun, promising a rare celestial event for skywatchers.

Meanwhile, anticipation is growing for the full operation of the Vera C. Rubin Observatory in Chile. Once it begins regular surveys of the southern night sky, scientists expect it could reveal dozens of new interstellar objects, ushering in a new age of galactic discovery.