It’s just a coincidence these are always close enough to the ground where people can see them and NEVER spotted by any of the 12000 commercial and military satellites in orbit, which are monitoring everything in the planet and in space and around them 24/7, tracking everything from heat signatures to photoelectric changes, infrared, radio frequencies to seismic shifts and gravitational waves and solar winds. Satellites that can tell if a match lights up on a missile base, or leaves start turning for the seasons, or a buoy gets lifted up by a tidal wave, or if you walk 5 feet. AND that have cameras that can read a car license plate on the surface or detect the subs changing spots and track the position of the mars rover.