A radio telescope is a large instrument used to detect radio waves emitted by celestial objects. Unlike optical telescopes that observe visible light, radio telescopes capture radio frequencies, allowing scientists to study phenomena such as pulsars, quasars, and cosmic microwave background radiation. They typically consist of a large dish that collects radio waves and a receiver that converts these signals into data for analysis. These telescopes can be found in various locations, often in remote areas to minimize interference from man-made signals. Some famous examples include the Arecibo Observatory and the Very Large Array. By studying radio waves, astronomers gain insights into the universe's structure, composition, and evolution.