This week Ancient Aliens: Declassified takes a look at whether much of the rapid technological development that took place in the 20th century was down to alien help.
Ancient astronaut theorists believe that extraterrestrials had contact with humans in the distant or recent past and provided valuable information on their technologies.
They point to the fact that human technology has advanced more since the start of the 20th century than in the thousands of years that preceded it.
One famous example they cite is the work done by the Nazis’ star aerospace engineer Wernher von Braun.
He worked on their advanced weapons like the V rockets and after WWII he went on to work for the U.S. government where he pioneered work on the space program.
They say that developments like the ballistic missile and ultimately the huge Saturn V rockets all stem from some contact he or others had with alien technology.
This four-hour special also examines the philosophy of Russian cosmism, whose proponents believe that humans originated in space and will one day return to the cosmos.
Ancient Aliens Declassified special airs at 8/7c on History Channel.