Although it sounds pretty cheesy (the science aspects suck), this is actually a first rate movie. Seems to be a low budget film and I don't recognize any of the stars. It was released in 1953 during the era of the "invaders from outerspace" but veers off in a different direction from most (another exception being "I Married a Creature From Outer Space").
The movie starts with some communications engineers trying to track down the source of a mysterious disturbance in their radio frequencies. They meet a lady who, along with her husband and a friend, has just been attacked by a strange person wearing what appears to be a deep sea divers outfit. Several other deaths occur and an oil refinery is blown up before it is realized the stranger is, in fact a visitor from outerspace who crashed on earth. From here the movie turns into a sensitive portrait of the alien's attempt to survive a hostile atmosphere and evade capture. Unfortunately, the protagonists realize too late what is going on and the alien dies (he is unable to survive in earths atmosphere for very long without his breathing apparatus).
Most of the films from this era dealt with horrible alien invaders hellbent on kidnapping earth women for deviant alien sex (one wonders if this would be the alien equivalent of bestiality?) and this film is a notable exception. Anyone with an hour to spare should check it out!
