(There was a comment that I was replying to about the realization that this was a transmitter and not just a receiver that was deleted ...) It was both. The A

(There was a comment that I was replying to about the realization that this was a transmitter and not just a receiver that was deleted ...) It was both. The Arecibo message was transmitted from there - https://en.wikipedia.org/wiki/Arecibo_message https://en.wikipedia.org/wiki/Arecibo_message > The entire message consisted of 1,679 binary digits, approximately 210 bytes, transmitted at a frequency of 2,380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 450 kW. There's also the field of radar astronomy (not radio astronomy) https://en.wikipedia.org/wiki/Radar_astronomy https://en.wikipedia.org/wiki/Radar_astronomy where you bounce of a signal off of an object in the solar system (such as an asteroid) > Radar provides the ability to study the shape, size and spin state of asteroids and comets from the ground. Radar imaging has produced images with up to 7.5-meter resolution. With sufficient data, the size, shape, spin and radar albedo of the target asteroids can be extracted. > ... > In August 2020 the Arecibo Observatory (Arecibo Planetary Radar) suffered a structural cable failure, leading to the collapse of the main telescope in December of that year. > There is one remaining radar astronomy facility in regular use, the Goldstone Solar System Radar.