Numerous large overlapping lava flows are shown in this Magellan radar image of Sapas Mons on Venus (8°N, 188°E). Sapas Mons is approximately 400 kilometers across and 1.5 kilometers high. Smooth (pahoehoe) lava flows typically appear dark in radar images, while rougher (a'a) flows will have a higher radar backscatter and so will appear bright in Magellan data. From this scene, we can infer that long lava flows on Venus are comparatively rough at the radar wavelength of 12 centimeters. The Big Island of Hawaii, which is approximately 130 × 150 kilometers in size, has been superimposed in blue for scale comparison.
JPL Magellan MGN P-38360.