Vangelis - Missing (Opening Theme) 

This is the theme music from the 1982 film, "Missing", directed by Konstantinos Gavras (AKA Constantin Costa-Gavras.) The film is based on a scandal that took place in Chile in 1973. Specifically, it is based on the disappearance of journalist Charles Horman. (Just for the record, the country is never referred to by name in the film, but its capital city, Santiago, is mentioned.)
Horman had attempted to expose a conspiracy between the American and Chilean governments to overthrow Chilean president Salvador Allende. Unfortunately, he was later kidnapped by forces loyal to the conspirators, triggering a manhunt. It was later discovered that Horman had been executed when his body was discovered in a morgue.
Jack Lemmon stars as Horman's father, Ed, and Sissy Spacek as Horman's wife, Beth.
One of Costa-Gavras's most effective techniques in the film is the manner in which it is established to be based on a true story in the opening scene, although the ending scene states that the American government denies the existence of the events.
Much like Michael Moore's "Fahrenheit 9/11", the film caused controversy for its portrayal of American interference in other countries' affairs, and was at one point banned in Chile because of its depiction of the Pinochet regime. (Speaking of Michael Moore, the overthrow of Allende and his replacement with Pinochet was mentioned in the "What a Wonderful World" montage in "Bowling for Columbine.") Nevertheless, Costa-Gavras was awarded the Palme d'Or prize at the Cannes Film Festival for his work. The film also won an Academy Award for Best Adapted Screenplay, and was nominated for Best Picture. In addition, Lemmon and Spacek were nominated for Best Actor and Best Actress, respectively, for their performances.
One of Vangelis's most beautiful soundtracks, "Missing" is at times haunting and often rather melancholy, helping to convey the loss felt by the protagonists, as well as the unstable political situation. Like "The Bounty", the soundtrack has never been released on CD despite much demand, although the opening theme was included on Vangelis's 1989 soundtrack compilation, "Themes."
The video itself consists of some photos taken by (and, in one case, of) the Hubble Space Telescope, combined with some footage from an educational film created by the Maryland Deptartment of Education and from a NASA documentary. Although it's kind of belated, this video could also be considered a comemmoration of the 20th anniversary of the HST's launch.
Please note that there's a slight editing error in one of the photos - the name of the website that provided the photo is clearly visible! I bet that might possibly kill the ambience for some of you, but I hope you'll forgive me for that.
Oh, and one other thing - and this is important - I watched part of the film shortly after I originally uploaded the video, and I discovered that the piece in the video is actually the film's ENDING theme, not the opening theme as stated in the title. Unfortunately, it's too late to change the title, seeing that the video had already been seen by thousands of viewers when I first uncovered this fact. I know I might get possibly flagged for this, but I hope you'll forgive me for this as well.