By using radar to probe through the permanent and thick clouds in the Venusian atmosphere and make observations of the surface, scientists at the American Arecibo Radio Telescope in Puerto Rico discovered the extensive highland on Venus that came to be called Maxwell Montes in 1967. In 1978, the space probe Pioneer Venus 1 went into orbit around Venus for the purpose of making radar observations of the Venusian surface. These observations made possible the creation of the first topographic map of the surface of Venus, and confirmed that a point within Maxwell Montes is the highest point above the average level of the planet's surface.