Planetary scientists have obtained remarkable features of the surface of Venus, which is always shrouded beneath thick clouds made mostly of carbon dioxide.

Earth-based telescopes have earlier discovered a number of remarkable features on Venus, including mountains, craters and volcanoes. However, conventional methods of observing Venus from the Earth does not provide clear images due to the planet's permanent cloud covering.

Combining the abilities of the world's largest fully steerable radio telescope, Robert C. Byrd Green Bank Telescope (GBT), and a powerful radar transmitter at the Arecibo Observatory in Puerto Rico, researchers performed a planetary survey of Venus from Earth and obtained detailed pictures of the planet's surface, featuring mountains, ridges and volcanoes. In a process called bistatic radar, Arecibo's radar signals passed through the atmosphere of Earth and Venus to hit the planet's surface and then bounced back to be received by the GBT.

The 100-metre incredibly sensitive telescope GBT is the largest fully steerable radio telescope in the world. It is located in the National Radio Quiet Zone and the West Virginia Radio Astronomy Zone where it is protected from unwanted radio interference to allow the telescope to make unique observations. Arecibo first obtained high-resolution radar images of Venus in 1988 and GBT in 2012, supported with coverage by Lynn Carter of NASA's Goddard Spaceflight Center in Greenbelt, Md. during early 2000 Astronomers used both sets of photos to study how the planet's surface changed over time.

Using the images, planetary scientists will now detect changes on the surface of Venus by carrying out further radar examinations. These changes could provide proof of active volcanoes or other geological processes. Understanding the volcanic activity present on Venus could help the scientists know about the planet's geological past and subsurface conditions.