Making contact with ET? Aliens may already know we’re here

We may already be signaling other intelligences beyond our solar system, without even trying. Kunyu City, in the Xinjiang Uygur Autonomous Region of northwest China, hosts huge sprinklers that are irrigating over 1,317 acres (533 hectares) of winter wheat fields on the southern edge of the Taklamakan Desert. Then there’s the world’s largest cluster of solar farms, a megaproject that covers 235 square miles (639 square kilometers) in Qinghai, China, high on the isolated Tibetan Plateau. And Earth is dotted with many other humongous, human-made structures like these. To an alien eye, they may be tell-tale signs of intelligent goings-on,…