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.

The newly discovered interstellar object 3I/ATLAS could be a piece of "possibly hostile" extraterrestrial technology in disguise, according to controversial research from a small group of scientists, ...

A strange interstellar object is hurtling its way toward our pale blue dot — and according to a Harvard astronomer, there's a chance it's not a benign asteroid or comet, but instead some harmful form ...