First time seeing this news thought it was a joke but turns out it's not. A few questions: 1. is it possible for a balloon to fly over pacific to U.S? 2. why we notice it after it has been at mid US? I think we could identify it starting from the west coast? 3. what makes it to be a Chinese balloon? I mean it could be from other country, right?

I tried to search answer but not finding useful information so far