An amazing interstellar object discovered last week, called 3i/Atlas, can be the oldest comet ever observed, possibly prior to the Solar System in more than 3,000 million years, the researchers have announced this Friday.
The comet is the third known object from outside the solar system that has been sighted in the “cosmic neighborhood” of the Earth and the first to arrive from a completely different region to our galaxy, the Milky Way.
Seven billion years
According to the astronomer of the University of Oxford, Matthew Hopkins, he could be more than 7 billion years old and be the interstellar finding “more relevant to date.”
Unlike the two previous objects that entered the solar system from other parts of the cosmos, 3i/Atlas seems to travel with an steep trajectory through the galaxy, which suggests that it originated in the thick disc of the Milky Way, a population of ancient stars that orbit above and below the thin plane where the sun and most stars reside.
“All non -interstellar comets, such as Halley, formed with the Solar System, so they are up to 4.5 billion years,” said Hopkins, which this week presents their findings at the National Astronomy Meeting 2025 of the Royal Astronomical Society in Durham and made this discovery when he had just presented his thesis.
“Interstellar objects can be much older and, of those who know so far, 3i/Atlas is, most likely, the oldest comet we have ever seen,” he added in a statement.
The object was first sighted on July 1, 2025 by the Atlas Exploration Telescope in Chile, when it was 670 million kilometers from the sun.
Rich in ice
Hopkins’s research indicates that, since 3I/Atlas is likely to be formed around an ancient star of the large album, it should be rich in water ice.
“This is an object from a part of the galaxy that we had never seen before. We believe that there is a 66% chance that this comet is older than the Solar System and that it has been wandering for interstellar space since then,” said another of the authors, Chris Lentott, presenter of the ‘The Sky AT Night’ program of the BBC.
As you approach the sun, sunlight will heat the surface of the 3I/Atlas and trigger the commentary activity, that is, the release of steam and dust that creates a bright comma and tail.
Lee: Webb Space Telescope: Imagine it as a camera so powerful that ‘View’ the lights of the galaxies
The first observations already suggest that the kite is active and that it is possibly bigger than any of its interstellar predecessors, the 1i/’Oumuamua (sighted in 2017) and the 2i/Borisov (2019).
If confirmed, it will provide clues to scientists about the role played by the ancient interstellar comets in the formation of stars and planets throughout the galaxy.
Discovery by surprise
The 3I discovery occurred almost by surprise when the researchers prepared for the start of exploration operations with the Vera C. Rubin Observatory, which will carry out an unprecedented exploration for a decade of the optical sky called space-time research as a legacy for posterity. Researchers believe they have potential to discover between 5 and 50 interstellar objects.
“The discovery of 3I suggests that the prospects for Rubin can now be more optimistic; we may find about 50 objects, some of which would be similar to 3i’s size. The news of this week, especially after Rubin’s first images, make the beginning of the observations even more exciting,” said another of the researcher Rosemary Doresey, from the University of Helsinki.
The team’s findings come from the application of a model, called ōtautahi-Oxford, developed during Hopkins doctoral research, which simulates the properties of interstellar objects based on their orbits and their possible star origins.
The new 3I/Atlas comet will be visible through a reasonable amateur telescope at the end of 2025 and early 2026.
With EFE information
Do you use more Facebook? Let us like to be informed
