Arecibo Observatory
Past attempts at capturing the surface of Venus were made using optical cameras. These observations could not penetrate through the planet’s top layer of thick clouds, leaving what lay under the surface a complete mystery.
However, since Arecibo did not rely on optical images but radio waves, it was able to break through the haze and create the first-ever radar maps of Venus’ surface.
This discovery led to the prospect that it may even be possible to map the surface of Venus at resolutions down to 2 kilometers. The US National Aeronautics and Space Administration (NASA) subsequently agreed to upgrade the telescope and provide funds for a 420 kilowatts (kW) transmitter for a closer look.