McDonald Observatory, astronomical observatory located on Mt. Locke, near Fort Davis, Tex.; founded in 1932, sponsored by the Univ. of Texas in cooperation with the Univ. of Chicago. Its equipment includes 107-in. (272-cm), 82-in. (208-cm), 32-in. (81-cm), and 30-in. (76-cm) reflecting telescopes. The 107-in. reflector, which began operation in 1968 as the third largest telescope in the world, was built under contract with the National Aeronautics and Space Administration. It was primarily used for the study of bodies within the solar system, particularly the planets, satellites, and asteroids, to gather information for possible use in future space exploration. Principal programs include research on interstellar molecules as well as the spectroscopic and photometric analysis of stellar, interstellar, and extragalactic matter. The observatory produces the "Star Date" radio program, providing a daily report of astronomical news and sky events across North America.