The interstellar comet 3I/Atlas, only the third object ever observed entering our solar system from outside it, may be nearly 12 billion years old—far older than the Sun.

New data from powerful telescopes, including the James Webb Space Telescope, show it has a chemical composition unlike any known solar system object, including unusually high levels of heavy water.

Scientists believe it likely formed in an extremely cold environment and may be a relic from an early era of galaxy formation.

While some speculation briefly suggested it could be artificial, NASA and other researchers have found no evidence of alien technology, The Guardian has reported.

The comet is now leaving the solar system permanently, offering a rare but fading opportunity to study an ancient visitor from deep space.