after several seconds i went outside because the airport is about 2 mi. off and planes fly over a lot each night.I am use to their sound.But this was very load and scary.The sound was like a train but slow and hummed and dull. i finally went outside because it sounded like it was so huge.The lights were just passing over head and pulsating in a line up.The lights were headed for our airport but this string of lights were several lights which took up the whole horizon.I noticed a plane coming in towards the airport with a red blinking light.I know they must have seen the lights,it would have been terrifying the sound.The lights took turns across the sky each pulsating off and on as the next light came on in alternating in sequence.Then there was a light below the line up(same color),all the lights were white.The lower light joined in the alternating of the others,each taking it's turn.Whatever it was the lights were perfectly spaced in a large line and flying really low and slow.I couldn't believe that our airport didn't put out something.I've never seen anything like it before.We live really remote in canyons and this was coming from the south.