I want to find out the name of a sci-fi movie I saw when I was kid in 1974. Aliens from a planet soon to be doomed due to an expanding sun appeared on Earth through some transporter-like device and sought our help. The movie sticks in my mind because, in spite of our efforts, we could not help and the planet was destroyed.
Adam Feller
9th Jan 2007
Chosen answer: Sounds like "This Island Earth (1955)".