Science fiction stories about “alien” invaders are often political allegories for anxieties around immigration. Now, a ...

Aliens could, in theory, reach Earth but would never truly go home again, according to physicists who say Einstein's laws of ...

To travel between solar systems, a spacecraft would need extremely sophisticated – if not impossible – technology.

Harvard professor Avi Loeb believes that aliens are not going to visit Earth in physical form, and would instead send a "technological device guided by AI". Their visit would not be fun either, and ...