The European Space Agency's Mars Express orbiter has captured striking new images revealing dramatic scars left by massive ancient floods on the Martian surface. The images show rugged landscape of chaos terrain and impact craters reshaped by water flowing across the red planet billions of years ago. High-resolution observations show regions where catastrophic flooding events carved massive channels and created chaotic terrain. The evidence of ancient floods is significant because it confirms Mars once had a wetter climate and suggests water was abundant enough to trigger planetary-scale hydrological events. These observations support the understanding that Mars underwent dramatic climate change. Early Mars was warmer and wetter than today's cold, dry desert world.