Chinese spy balloon guided by AI, hard to shoot down, says US expert

China's first surveillance balloon that the Pentagon found flying over sensitive US ballistic missile sites may be guided by advanced artificial intelligence technology, a US expert said on Friday. A second Chinese surveillance balloon was later spotted over Latin America, the Pentagon said, without specifying its exact location.

William Kim, a tracking balloon specialist at the Marathon Initiative think tank in Washington, said the balloons are a valuable means of observation that are difficult to shoot down. Kim said the first Chinese balloon looked like a normal weather balloon but had different characteristics. It has a relatively large, visible "payload" -- electronics for guidance and information collection, powered by large solar panels. And it appears to have advanced control technologies that the US military has not yet released into the air.

Artificial intelligence allowed the balloon, simply by reading changes in the air around it, to adjust its height to guide it where it wanted, Kim said. "Before, you either had to have a strap ... or you just send it up and it just goes where the wind blows you," he said.

Kim said that as satellites become more vulnerable to attacks from Earth and space, the balloons have distinct advantages. First, it doesn't just pop up on radars. "They're non-reflective materials, they're not metallic. So even if these balloons expand to quite large sizes, detecting ... the balloon itself is going to be a problem," he said.