"Not gonna lie. First, I thought this was a #ufo. Then, I thought it was @elonmusk in a Wizard of Oz cosplay scenario," tweeted eyewitness Chase Doak. "But it was just a run-of-the mill Chinese spy balloon!" The U.S. is tracking what it says is a “high-altitude surveillance balloon” moving over the country. On Friday, however, the Chinese Foreign Ministry denied that the aircraft is a spy balloon, instead insisting it's simply a civilian airship used for weather research.