300-Foot Transit Radio Telescope, The National Radio Astronomy Observatory
View of the 300-foot transit radio telescope-the world's largest movable radio telescope. The inside surface area of the dish is 1.8 acres and its maximum height above the ground is 225 feet. Its movement has been restricted to elevations along a north-south line. Astronomical programs include measurements of hydrogen gas in our galaxy, in nearby galaxies, and for studies of distant and faint radio sources.