In 1977, a radio telescope in Ohio caught a powerful narrowband signal from deep space. It lasted 72 seconds, looked exactly like an interstellar broadcast should — and it has never been heard again.

In 1908, a blast many times more powerful than the Hiroshima bomb flattened some 80 million trees across a swath of Siberia larger than a major city. It left no crater, no confirmed fragment, and a question science still cannot fully close: what came out of the sky that morning?

Since 1795, treasure hunters have poured fortunes — and six lives — into one hole in the ground off Nova Scotia. Nothing conclusive has ever come out of it.

A 15th-century codex filled with impossible plants, bathing women and a script no one has ever decoded has defeated medieval scholars, WWII codebreakers and modern artificial intelligence alike.

A diver surfaced screaming about a heap of corpses on the seabed; they were bronze statues - and beside them lay a 2,000-year-old geared computer. New research keeps making it stranger: it tracked the lunar year with uncanny precision, yet its gears may have jammed when cranked.

In 1590, John White returned to Roanoke Island to find 115 colonists gone — and a single word carved into a post. Modern archaeology may finally be closing in on where they went.

In July 1518 one woman began to dance in a Strasbourg street. Within a month hundreds had joined her, and the city's official cure was to hire musicians. Five centuries later, no one can say what really happened.

He walked out of nothing into a Nuremberg square, claiming a lifetime in a dark cell. Five years later a stranger's knife — or his own — killed him. Two centuries and a 2024 DNA test later, we know who he was not, and still not who he was.

Abandoned in the Arctic ice in 1931, the crewless SS Baychimo went on sailing by herself for nearly four decades - sighted, boarded, stripped of furniture and a whaleboat, and lost again, until she vanished for good.

Her final radio call came in at full strength - she should have been minutes away. Instead she vanished. After a sonar sensation that turned out to be a rock, an expedition sailing in July 2026 believes the answer may have been visible in photographs since 1938.

Hundreds of giant figures were etched into a Peruvian desert two thousand years ago. We know exactly how they were made. We still don't know why.

For 35 years, 97 letters on a copper sculpture at CIA headquarters have defeated the world's best codebreakers. In November 2025 the answer was sold for $962,500 — to an anonymous buyer sworn to keep it secret. The mystery was sold. It was not solved.