Scientists propose examining lunar soil for tiny engineered particles that could preserve evidence of civilizations long since vanished.

Add Yahoo as a preferred source to see more of our stories on Google. The great physicist Enrico Fermi first posed the challenging question over half a century ago, wondering why we appear to be alone ...

Humans have created countless inventions that shape our lives in amazing ways. Some are practical, some are revolutionary, and some are simply fascinating. But if aliens suddenly appeared, which ...