The American military shot down a high-altitude object over Lake Huron on Sunday afternoon, the Pentagon said. Another unidentified object was shot down over northern Canada on Saturday, and on Friday, an unidentified object was shot down in the airspace of Alaska, according to CNN.

According to two US officials, all three objects looked different. The official said they were about the same size. Two officials said none of the three objects likely had an engine, although the wreckage still needs to be examined to be sure.

“I can’t figure out how I stay in the air. It could be a gas-type balloon inside the structure, or it could be some sort of propulsion system. But they’re obviously capable of staying in the air,” NORAD commander Gen. Glen VanHerk said Sunday.

Several officials said the downed objects in Alaska and over Canada likely had payloads, meaning the object was carrying something.

Here’s what we know about the objects now:

• Off the coast of northern Alaska: According to several US officials, it was described as a metallic object that broke into several pieces when it hit the ice as it fell. That suggests it may have had some structure, but officials won’t know for sure until the object is found.
• Over Lake Huron: CNN reported Sunday that the latest object to land over Lake Huron was “octagonal” in shape, with dangling ropes and no apparent payload, according to a senior administration official. The Pentagon said on Sunday that it was traveling at an altitude of 6,000 meters when it was shot down.
• Over northern Canada: A downed object over Canada’s Yukon territory looked like a hot air balloon with a metallic payload hanging below it, officials said.

Canadian Defense Minister Anita Anand described the object as a “cylindrical object” smaller than the Chinese reconnaissance balloon that was shot down off the coast of South Carolina a week earlier.

Previous descriptions of the objects’ appearance highlight the difficulty for administration officials in determining their purpose or origin. Officials could not say what the objects were, and previous descriptions did not provide additional clarity.

Officials had difficulty distinguishing the three objects shot down in the past three days from the Chinese balloon shot down over the Atlantic Ocean. The three later objects were smaller in size and flew at a much lower altitude.

• VIDEO The White House says there is no evidence of extraterrestrial activity in the US / “This is a worldwide problem” / “We are still evaluating what the octagonal flying object was”

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