This world is full of mysteries and here are five of those that will keep you up at night…thinking!
1. The Black Knight Satellite

Do aliens exist or not? This discussion has been going on for years. Random sightings and unexplained phenomenon spark this debate on a regular basis. One such case is the Black Knight Satellite. It is believed this satellite has been orbiting the earth for over 13,000 years and is of extraterrestrial origin. What makes it more interesting is the fact that the first Black Knight launch happened in 1958 (as per NASA’s website) and the mysterious satellite was discovered in 1954.
2. The Dancing Plague

Back in 1518 a woman walking in the street started to dance for no reason and with no music. The woman did not stop dancing for several days and then others started to join her. It is believed the number of dancers reached up to 400. Things became so intriguing that a dancing stage was built and musicians were called. Some dancers died of exhaustion while others suffered fatal heart attacks. Doctors and religious bodies were called into investigate but no conclusions could be made. Some called it a psychogenic illness while others called it epilepsy; what it really was, nobody knows.
3. Wow

This incident is perhaps one of the strongest evidence of alien existence. In 1977 The Search for Extraterrestrial Intelligence’s volunteer Jerry Ehman received a signal that lasted for 72 seconds and sent his radio waves surging. It is believed the signal came somewhere from the 120 light years away star named as Tau Sagittarii. Ehman took the print out of his readings and after circling a few combinations wrote “Wow” on the paper. What makes the signal special? It uses the frequency that cannot be dubbed as noise and yet cannot be intercepted while travelling. However, after that one incident the signal could not be located again.
4. Déjà vu

Ever had the experience where you find yourself in a new situation but it doesn’t feel new at all? The same exact location, the same actions and reactions; everything had happened before. Sometimes you visit a place for the first time but you get the feeling you had been there before. This feeling is called Déjà vu. Even though many studies have been made to understand it but no conclusive results have been found. From reincarnation to out of body experiences and memory glitches, there are many theories circulating, but none has been dubbed conclusive.
5. Kryptos

This is straight out of a Dan Brown novel and what makes it more fascinating is its location, outside the CIA headquarters. The sculpture called as Kryptos has a coded message written on it, which to this day has not been cracked. Kryptos, meaning “hidden” or “secret” in Greek, was first discovered in 1990. Many cryptographers, over the years, have tried to decode the message and a few were able to crack a few lines. This is not all, the Kryptos is surrounded by a few other objects that are believed to be crucial to solving the mystery. Kryptos was built in 1989 by Jim Sanborn, an artist from the U.S. The part of the message that was decoded can be found on the Internet.