Professor Avi Loeb, a theoretical physicist and cosmologist from Harvard University, told MailOnline why he thinks a new ...

British astronomers may have solved the mystery of an "interstellar object" hurtling towards our planet. Scientists believe the mysterious interstellar visitor may be the oldest comet ever observed.

A mysterious object, first observed hurtling across the solar system on July 1, has now been identified as "very likely to be the oldest comet ever."  The interstellar object 3I/ATLAS could be around ...

A newly discovered object from deep space may be the oldest comet ever observed—possibly more than 7 billion years old, and ...