Nine experienced hikers cut their way out of their tent into a freezing night and ran toward almost certain death. Decades later, we still don't fully know why.
It's 600 years old, written in a language that appears in no other document on Earth, and the world's best codebreakers have all failed.
For decades it was the ocean that swallowed ships and planes without a trace. The real explanation is less supernatural β and more interesting.
In 1977 a telescope caught a burst from deep space so striking that an astronomer circled it and scrawled one word. We've never heard it again.
Etched into a Peruvian desert are enormous figures β a monkey, a hummingbird, a spider β so large they can only be seen from far above. The question is why.
In a quiet town in New Mexico, a small number of people hear a low, maddening drone that instruments struggle to detect. No one has explained it.