Mexico City is one of the fastest subsiding cities in the world, and the NASA-ISRO NISAR satellite is tracking the rate.
The NASA-ISRO Synthetic Aperture Radar, or NISAR, is now in full operation, tracking changes in Earth's surface to a precision within a centimeter.
Mexico City is sinking, and a powerful new orbiting satellite that's monitoring changes in land levels all across the globe has discovered how quickly this is happening.
