The Man from Planet X (1951) on Netflix

A New York City newspaper reporter flies to a remote island off Scotland, on an invitation from a scientist who is a long-time friend, to cover the news of the approach to earth of a previously-unknown planet, which the scientist has called Planet X. While awaiting the calculated date of it closest approach to Earth, they discover a torpedo-shaped craft in which an agent of Planet X, peacefully disposed, has landed to make preparations for further landings of X-people when the planet reaches its closest proximity to Earth. The scientist's assistant crosses up the friendly visitor, who depends on a tank of X-atmosphere for survival. The Man from Planet X, using a mesmeric ray, captures the scientist, his daughter, the assistant and several townspeople. The reporter calls Scotland Yard. Sherrill Corwin, a distributor, gave this film a test-run at the San Francisco Paramount on March 9, 1951 (after screening it in Hollywood for the trade-paper reviewers on March 8) before buying the distribution rights from Aubrey Wisberg and Jack Pollexfen's Mid-Century Pictures production company.