Rescue missions are won or lost in minutes, and increasingly, in the accuracy of a single satellite image. Picture a rapidly spreading wildfire, and a satellite passing overhead trying to make sense of what it sees. Optical cameras find only smoke, an opaque grey wall with nothing useful behind it. Radar can cut through that same smoke well enough, but the image it returns takes time and expertise to interpret, time a response team on the ground cannot always spare.

A stretch of land can look completely trustworthy from the surface. The grass is even, the ground feels solid, and nothing visible hints that anything could be wrong. But underneath, soil can be shifting, slopes can be losing their grip, and the early signs of subsidence can already be taking shape. By the time any of it becomes visible, it is usually too late to do much about it.