Lake Huron
There are 12,000 highest tech satellites orbiting the earth. They monitor everything from heat signatures to infrared changes to radio frequency, solar waves, you name it. They have the highest grade cameras available. they can read a license plate on the ground or tell if someone farts on a missile base.
No ‘ufo’ has ever passed any of them. No ‘ufo’ is ever in low orbit. All ‘Uris’ are in airplane airspace. They originate from the ground. All of them.
Now whether there are ‘aliens’ launching from the ocean or Antarctica, that isn’t ruled out. But nothing comes past earths perimeter of satellites