Mysterious space object may be oldest comet ever discovered, scientists say

By Ruth Lawes

A mystery interstellar object has been identified as the "oldest comet ever seen", according to scientists.

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The Oxford University team believes the comet could pre-date the solar system at more than seven billion years old.

It would make the comet named 3I/Atlas only the third object discovered to have existed outside of the solar system.

Scientists believe 3I/Atlas was formed in the Milky Way's "thick disk", part of the galaxy that extends farther above and below the galactic plane and contains older stars than the thin disk.

But it was only spotted for the first time earlier this month by the Atlas survey telescope in Chile at a distance of 670 million km from the Sun.

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Speaking about 3I/Atlas's discovery, Oxford University astronomer Matthew Hopkins told BBC News: "We're all very excited by 3I/Atlas.

"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."

In May, scientists were left stumped after another space object was sending an "unexpected" pulsing signal to Earth that was "unlike anything ever seen before."

Nasa scientist Richard Stanton, who discovered the signal, said he couldn't rule out the possibility that the signal is coming from an alien civilisation.

"In over 1500 hours of searching, no single pulse resembling these has ever been detected," he added.

“The fine structure in the star's light between the peaks of the first pulse repeats almost exactly in the second pulse 4.4s later. No one knows how to explain this behaviour”.

Theories for the pulse include birds and "common signals which can come from meteors, satellites, airplanes, lighting, atmospheric scintillation, and system noise.

However, Stanton said the signals from those sources “are completely different from these pulses."

"None of these explanations are really satisfying at this point," said Stanton.

"We don't know what kind of object could produce these pulses or how far away it is.

"We don't know if the two-pulse signal is produced by something passing between us and the star or if it is generated by something that modulates the star's light without moving across the field.

"Until we learn more, we can't even say whether or not extraterrestrials are involved!"