A mystery interstellar object discovered last week is likely to be the oldest comet ever seen – possibly predating our solar system by more than three billion years, researchers say. The "water ...

I/ATLAS might be over 7 billion years old, a new study reports, which would make it the oldest comet known. But experts caution we need more data.

A mystery interstellar object discovered last week is likely to be the oldest comet ever seen—possibly predating our solar ...