If it looks like something that could transport you into the future, in a sense it is. A spaceship-sized hoop suspended from a helicopter is actually part of an advanced water detection system. The information it’s gathering, could help determine the future of California’s water supply – and where we store it. … For several years, [Stanford professor Rosemary] Knight has been conducting aerial surveys using an electromagnetic sensing system. She says the technology is able to penetrate the ground, yielding vital data on the geology of natural groundwater basins. 3D maps pinpoint attractive sites, made up of materials marked in red, like sand and gravel, that allow water to sink in.