We celebrate it each year by pulling pranks on one another, but nobody is quite sure how it all started.
Footage of a strange spinning object has emerged online and nobody seems to be able to tell what it is.
Researchers have created a life-sized model of what the typical office worker of the future might look like.
The US military's notoriously secretive miniature space shuttle is back and nobody knows what it has been up to.
This mystery animal was captured on camera next to a fishing boat and nobody seems to know what it is.
Russia has finally determined who or what created the hole on the ISS... but nobody else is getting to know.
Known as LEX, this bizarre new wearable invention has been described as 'an extension of your body.'
An unexplained malady has befallen beachgoers along the Essex coast and nobody knows what's causing it.
A woman who had been shopping in New York recently returned to her truck to find a dead body in the back.
Known as the 'Methuselah star' due to its extreme age, this nearby stellar body may predate the Big Bang.
A growing body of evidence points to a more complex explanation for the abandonment of the historic site.
A picturesque loch in the Scottish Highlands has been gradually disappearing and nobody is quite sure why.
Scientists have discovered what is thought to be the oldest known person with this rare congenital condition.
Scientists now believe that humans, like birds, may be able to sense the Earth's magnetic field.
Astronomers have picked up a very unusual repeating signal from a distant galaxy and nobody knows what it is.
A mysterious 'earthquake' rippled around the entire world earlier this month and yet nobody felt a thing.
A deep sea remote-operated vehicle recently captured footage of a unique species of eel with a very big mouth.
There is a growing body of evidence to suggest that young blood can help to treat age-related diseases.
The number of people reporting sightings of UFOs has been in sharp decline and nobody is quite sure why.
Scientists believe that they have identified a body of water situated beneath the planet's south polar ice cap.