On February 4 the U.S. shot down a massive Chinese surveillance balloon over the Atlantic Ocean just off South Carolina, after it spent days traveling across the country. As Americans turned their eyes to the sky, it became apparent that the object was not alone: news soon broke that another Chinese spy balloon was floating over Latin America, and that several such balloons had encroached on U.S. airspace since 2018—and had evaded early detection at the time. China has claimed that the balloon shot down last week was merely a weather-monitoring station blown off course. But the U.S. has since recovered sensors and other electronic equipment from the wreckage, which indicate that it was likely used for eavesdropping on electronic signals. Chinese officials also claimed that the U.S. has sent surveillance balloons over their country, but U.S. officials deny this.

With attention heightened, over the past few days the U.S. shot down three more airborne objects: one off the coast of Alaska on Friday, one over Canada on Saturday, and one over Lake Huron in Michigan on Sunday. Much remains unknown about the three most recent objects, including where they came from, if they carried surveillance equipment and whether they were even balloons or some other airborne craft.

Here is everything we know—and don’t know—about all the balloon brouhaha.

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