It's supposed to be the most common form of matter in the universe, but nobody has ever actually seen it.
Astronomers in Australia have discovered a strange radio source and nobody knows what it could be.
The long-lived space probe has been sending back some unusual data and nobody can figure out why.
Police in San Francisco recently pulled over a vehicle only to find that there was nobody in the driving seat.
A jogger recently came across this indescribable creature and nobody seems to know what on Earth it is.
The latest mission of the mysterious space plane has so far lasted 500 days and nobody knows what it's up to.
The clip shows the body of some futuristic aircraft at Lockheed's Helendale Radar Cross Section Facility.
A woman in New Zealand has been charged with attempting to smuggle hundreds of cacti into the country.
The mystery of a body found in a coffin on a moor 100 years ago continues to endure even to this day.
Police in South Carolina are investigating after a body was found by a group of amateur ghost hunters.
Experts are attempting to solve the mystery of an unidentified man who washed up on the Isles of Scilly.
The terrifying scenario became a reality for one young woman who recently 'died' at her home in Detroit.
The US government has confirmed that it has set up a body dedicated to investigating the UFO phenomenon.
Scientists have been studying how a prehistoric creature named Tanystropheus supported its insanely long neck.
The 'Ghost Adventures' crew recently found possible evidence of human remains at Joe Exotic's old zoo.
An increasing body of evidence suggests that Mars may have once had its own spectacular ring system.
An inscribed stone tablet dating back 2,000 years may not be about Jesus' body as was previously believed.
Scientists have identified one of the more unexpected ways in which the body changes while in space.
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.