A hoax 'alien invasion' alert in Brazil caused panic and amusement, revealing vulnerabilities in emergency systems.

The best alien invasion movies feature the most exhilarating stories about extraterrestrial visitors, from War of the Worlds to Annihilation.

Aliens are real. Or maybe not. The possibility of mystical beings watching over us or even walking among us is not just the ramblings of the fringe and Reddit users, but a key political and societal ...