There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
The Platypus used to be considered a myth like Bigfoot and the Yeti.
18
In 1968, a car driven by bank employees was pulled over by a motorcycle cop claiming the car had been rigged with a bomb. The cop got under the car to “defuse” the device. When the car started to smoke, everybody ran. Then the “cop” just drove the car away. The 300,000,000 Yen robbery remains unsolved to this day.
20
There's a mysterious dwarf planet between Mars and Jupiter called 'Ceres' which has never been visited by spacecraft or photographed in detail, however, Earth-bound telescopes reveal a large bright shining spot on the surface of this planet, the origin and nature of which are unknown.
5
A waterfall known as The Devil's Kettle empties water into a hole and nobody knows where it ends up!
18