One expert has an explanation for mysterious grids seen in Google Maps images of China’s Gobi Desert, Fox News reports: The 20-meter-wide zigzagging white lines are calibration targets for spy satellites, according to Jonathon Hill, a research technician and mission planner at the Mars Space Flight Facility at Arizona State University. Satellite cameras focus on the grids and use them to orient themselves in space.

Hill, who works with images of the martian surface taken by rovers and satellites as well as data from Earth-orbiting NASA instruments, said the calibration targets are larger than might be expected — 1 by 1.8 kilometers — suggesting that the satellite cameras they are being used to calibrate have surprisingly poor ground resolution.

A nearby Stonehenge-like arrangement of structures is likely a calibration/test target for orbital radar instruments, Hill said. “I think we’re seeing some sort of military zone/test range, which explains the large amount of equipment and technology in an otherwise remote area,” he said. “Sometimes the truth can be just as interesting, if not more so, than the conspiracies that people come up with.”


READ IT AT: [Fox News]