Officials across multiple government agencies are now working to determine who is behind the Colorado drones.
As the end of the year approaches, we take a look back at our most popular stories of the last twelve months.
Inventor and scientist Nikola Tesla had more than a passing interest in Egypt's archaeological wonders.
An extensive investigation has failed to solve the mystery of how a human bone ended up in a clothes shop sock.
Plans detailing the layout and security of the building recently vanished into thin air during renovation work.
Perplexing CCTV footage has emerged showing a display case moving up and down all by itself.
Valkenswaard residents have been hearing loud ominous trumpet sounds seemingly coming from the sky.
Authorities are investigating what might have caused an entire flock of starlings to suddenly drop dead.
A passenger who sat near Cooper during his infamous plane heist has spoken out about his experience.
A spate of unsolved animal killings involving occult symbolism have been reported in the south of England.
The unexpected discovery was made under King High School in Tampa after a tip-off from a local historian.
A girl who happens to look uncannily like the young activist has been spotted in an old archive photograph.
People across America awoke on Thursday to find unexplained text messages on their mobile phones.
Remarkable aerial footage shows a crop circle that is a completely different color to its surroundings.
Two climbers ascending California's second-highest peak recently uncovered a decades-old mystery.
A family in the Netherlands has been rescued after being kept in a secret room waiting for the end of the world.
Authorities investigating a spate of mystery bird deaths have been unable to come up with an explanation.
Unexplained markings that have appeared on pavements around Thornhill have left officers scratching their heads.
Scientists have been struggling to explain a series of fires sparked by an object that fell over Chile recently.
Police have been investigating the case of a real-life Pennywise who has been menacing a mother and son.