Originally Posted by Philistine

Venus is thought to renew its crust and shed internal heat (which is what plate tectonics does for earth) in a different way. Most of the time, its crust is stable and motionless. However, over the course of hundreds of millions of years, heat builds up in the planet. This heat is then released all at once, melting and renewing the entire Venusian surface . That explains why there are no really old craters on Venus.