Comparison of the roughness scaling of the surface topography of Earth and Venus.

We report the scaling behavior of the Earth and Venus over a wider range of length scales than reported by previous researchers. All landscapes (not only mountains) together follow a consistent scaling behavior, demonstrating a crossover between highly correlated (smooth) behavior at short length scales (with a scaling exponent $\alpha$=1) and self-affine behavior at long length scales ($\alpha$=0.4). The self-affine behavior at long scales is achieved on Earth above 10 km and on Venus above 50 km.