Over the years, multiple mysterious objects have been spotted hovering in the sky, fuelling the belief that unidentified flying objects (UFOs) do exist. In the US, Project Blue Book was a series of systematic studies conducted by the country's Air Force to investigate these sightings.

Between 1947 and 1969, a total of 12,618 sightings were reported, of which 701 cases remained "unexplained". Although the documents are now declassified, there is still a huge amount of interest among people to know more about the unexplained events.

History Channel is coming up with a scripted drama series titled Blue Book. The 10-episode series will chronicle the top- secret U.S. Air Force-sponsored investigations into UFO-related phenomena that occurred in the 1950s and the 60s.

With an intriguing subject, the series will be executive produced by Oscar winner Robert Zemeckis. Created and written on spec by David O'Leary, the show has roped in big names in the television industry as its lead cast, Deadline reports.

After immortalising the vicious Little Finger aka Lord Petyr Baelish in the Game of Thrones, Aidan Gillen is set to enter the world of unexplained mysteries by playing Dr. Allen Hynek – a brilliant astrophysicist, family man, and UFO sceptic who is recruited as the Chief Scientific Advisor for the "Project Blue Book."

He will be joined by Michael Malarkey, famed for his role Enzo in hit series The Vampire Diaries. He will play the character of Captain Michael Quinn, a decorated WWII hero. In the scripted drama, Quinn is selected to run Project Blue Book, a new Air Force division investigating UFO phenomena and will have intellectual clashes with his Blue Book partner Hynek.

History Channel is yet to announce the filming details and the premiere date of the show. The series has already generated huge interest among UFO enthusiasts for its picks. While the list of mysterious UFO sightings is pretty long, the series may pick few popular incidents for the plot.

It remains to be seen, how History Channel will narrate the UFO sightings in its scripted show. In its closure report, the Air Force claimed that "no UFO reported, investigated, and evaluated by the Air Force has ever given any indication of threat to our national security. There has been no evidence submitted to or discovered by the Air Force that sightings categorized as "unidentified" represent technological developments or principles beyond the range of present-day scientific knowledge; and there has been no evidence indicating that sightings categorized as "unidentified" are extraterrestrial vehicles."