The film is dedicated to a solar eclipse that was observed over a large territory of the Soviet Union on February 15, 1961. Researchers from the Crimean and Byurakan (Armenia) Observatories at telescopes and other instruments, including: AB Severny, Gnevyshev and others. Foreign scientists are present at the observation of the eclipse at the Crimean Observatory, including: Harold Zirin (USA), Raymond Mishar and Oliver Gauthier (France), Jiri Lexa, Joseph Tremko, Vera Khokhlova (Czechoslovakia). Scientists at telescopes in Rostov-on-Don, Sverdlovsk. Flying Observatory - Tu-104 aircraft in the air. Astronomers at the equipment in the aircraft cabin. Different plans for a solar eclipse, including a complete one.