From the Greys to the Nordics, these aliens appear frequently across abduction stories and science fiction tales.

A polarizing Harvard astronomer known for splashy theories about alien visits has been tapped by the Trump administration to lead a team of outside scientists to study the national security risks ...

A controversial Harvard University cosmologist who has suggested alien lifeforms could be sailing into the solar system disguised as meteors is leading the Trump administration’ ...

Avi Loeb is leading a new Science Advisory Council tasked with finding the origin of unidentified objects spotted by military pilots and others. It's part of a broader White House effort studying ...