The interstellar visitor Comet 3I/ATLAS passed Earth with Harvard astrophysicist Avi Loeb saying it could be an alien probe.

A mysterious cigar-shaped object spotted tumbling through our solar system last year may have been an alien spacecraft sent to investigate Earth, astronomers from Harvard University have suggested.

A relic from the beginning of the galaxy has finally come out of the sun's shadow. It gives us a rare look at a cosmic ...

I/ATLAS has passed its closest point to Earth, meaning we will soon lose sight of it for good. Some scientists want to send a spacecraft to chase down the alien comet — or the next interstellar object ...