two yellow light subjects with stable speed but changing their place with each other crossed the sky in a straight way in plain heightsWe were 4 on the roof and we saw 2 subjects like stars but a little yellow. hey had no sounds. they were crossing the sky in a straight line but they change their place with each other frequently in 180 degrees and then they return to their previous situation. with this harmony they croosed the sky with a stable speed. their light were mat and turbid. they went further and further till they disappeard.