Something is happening on a highway cutting through the US southwestern desert. A string of cars has pulled over on the hard shoulder, the drivers standing together and pointing into the distance. Another car is flagged down as it approaches. “You have got to see this,” urges the breathless onlooker. “It’s aliens for sure.”

He points to a bright light moving in the sky. It is not an aircraft, a star, or anything else any of them have seen before. The driver is in the uniform of a Major in the USAF. He gives a wry smile. “Don’t worry,” he says.