The U.S. says it is tracking a suspected Chinese surveillance balloon that has been spotted over U.S. airspace for a couple days. The Pentagon decided not to shoot it down over concerns of hurting people on the ground. A senior defense official says the U.S. has “very high confidence” it is a Chinese high-altitude balloon, and says it was flying over sensitive sites to collect information. One of the places the balloon was spotted was Montana, which is home to one of the nation’s three nuclear missile silo fields at Malmstrom Air Force Base, Montana.