I/ATLAS isn't just fascinating because it is the third interstellar visitor found in the solar system; new research suggests it's also the oldest comet ever seen, at over 7 billion years old.

The solar system has an uninvited guest that is currently shooting toward us on a one-way trip through our cosmic neighborhood.The newly discovered interstellar visitor, named 3I/ATLAS, is only the third of its kind ever seen.

Astronomers tracking an interstellar object flying through the solar system think it comes from a star at least 8 billion years old, almost twice the age of our sun