This movie really, really freaked me out when I was a kid

This weird 1969 film was made by the same gang that years later would give us the Space 1999 TV series.



This is from the film's unusually long and detailed Wikipedia entry:

Doppelgänger is a 1969 British science-fiction film directed by Robert Parrish and starring Roy Thinnes, Ian Hendry, Lynn Loring and Patrick Wymark. Outside Europe, it is known as Journey to the Far Side of the Sun, which is now the more popular title.^[1][2] In the film, a joint European-NASAmission to investigate a planet in a position parallel to Earth, behind the Sun, ends in disaster with the death of one of the astronauts (Hendry). His colleague (Thinnes) discovers that the planet is a mirror image of Earth.