But a new study suggests that beneath its harsh surface, Venus may still be an active and changing planet. These long cracks form when a planet’s crust is pulled apart by forces deep inside. On Venus, however, some rift valleys are far larger, stretching for up to 10,000 kilometers. Unlike earlier models, which were simpler and mostly two-dimensional, the new simulations provided a much more realistic picture of how the planet’s crust behaves. The simulations showed that young or still-active rift valleys develop broad, raised edges known as rift flanks.