Aliens have long been a staple of science fiction. Yet the possibility of intelligent life beyond Earth is more than a matter of imagination—it is also a subject of serious scientific inquiry.

For generations, artists and science-fiction writers have imagined alien landscapes beneath twin sunsets. The image became iconic in popular culture long before astronomers confirmed that planets ...

A new study from researchers in Japan suggests that a better way to search for alien life might be to look for suspiciously similar planets that are close to each other. The idea is that if life has ...