Before Deep Impact and Armageddon, there was When Worlds Collide.
Astronomers in South Africa--one played by Hayden Rorke, who went on the play Dr. Bellows in 'I Dream of Jeannie'--discover a star is on a collision course with Earth. Along with associates in America, most notably Larry Keating, in the role of Dr. Hendron, they try to convince a skeptical world that doomsday is just around the corner.
Unable to convince the world of the coming calamity, they set to work in building a rocket of salavation--to fly to what they believe is a habitable planet circling the star eventually named Zyra (the planet, they name Bellus). The rocket building is funded by a meglomaniac wheelchair-bound millionaire name Sydney Stantion--played wonderfully wicked by character actor John Hoyt. You also have Frank Cady, looking very young yet still very bald, who went on to greater fame in Green Acres.
As doomsday draws nearer, the rest of the world becomes convinced of what is to happen. As Hendon put it early in the movie, "Even a layman will be able to see the danger."
I didn't really find Richard Derr convincing as ladies' man Dave Randall. He was just a little too much Howdy Doody in the face to pull it off. The lovely Barbara Rush play Dr. Hendon's daughter, Joyce, and Randall's eventual love interest. By the way...a little Trek trivia here...Barbara Rush was the real-life wife of actor Jeffrey Hunter, who played Captain Christopher Pike in the original Star Trek pilot in 1964 (ultimately played by Shatner, of course).
The story does manage to build some tension, but the film is more genre than epic. There are some nice scenes, such as the U.N. scene (they must have spent some money on that) and closeups of the rocket. Unfortunately, the effects fall apart upon landing on Bellus.