Magellan mapped Venus with radar. On those maps, what do the brighter areas mean?

1. Thick cloud hides the surface of Venus from ordinary cameras. 2. Radar solves that, because radio waves pass straight through the cloud. 3. A radar map is built from the strength of the reflected signal, not from visible light. 4. Rough ground scatters the beam back strongly and so appears bright. 5. Smooth ground reflects the beam away and so appears dark. 6. Brightness therefore reports texture rather than temperature. 7. Height is shown on these maps only when color is added separately for elevation. 8. Venus has no liquid water at all, so wetness cannot be what the brightness measures. _Source: OpenStax Astronomy (CC BY 4.0), section 10.2 The Geology of Venus_