Well there appears to be luminaries in the sky that also seem to keep a schedule.  Aside from that nothing else can be proven.  Do you think they are giant balls of gas millions of light years away or simple lights in the night sky put there by an engineer.  maybe it's something un-thought of.  All we know is there are lights that move in a pattern.  If anyone claims otherwise they are spouting bullshit.  Scientist included.