The cloud cover on Venus is so dense that it cannot even be penetrated by cameras aimed at the surface, mounted on satellites in orbit around the planet. It is only possible to ‘see’ the structures on the surface of Venus with radar information. The first wide-ranging, high-resolution topographical mapping of Venus was carried out in the 1990s by the Magellan NASA probe.
This picture part of the southern hemisphere of the planet, ranging from about 15 degrees south to 80 degrees south; the zero meridian runs vertically through the middle of the image. The colouring reflects altitude readings: blue areas are low-lying regions, the ochre and brown – orange areas are the highlands, while the areas in between are coloured green.
The area around the Lada Terra highlands at the bottom of the picture, with the notable tectonic ring structure, Quetzalpetlatl Corona, and the areas to the north were subjected to thorough investigation in the first years of the European Space Agency (ESA)’s Venus Express mission with the VIRTIS (Visible and Infrared Thermal Imaging) spectrometer. Anomalies in the heat radiation readings from volcanic structures on the surface of Venus obtained with VIRTIS (in relation to the forecast values) allow us to draw conclusions about the geological development of the region.