Two lights moving slowly at tree top level around our house with no sound.

I was outside our house which is on top of a hill.  I was 18 at the time.  I noticed lights on the horizon in several directions which look like half moons.  I then noticed two small lights moving slowly through the ski.  I thought it was an airplane, until it stopped, and changed direction back the way it came.
 	I observed this for about five minutes during which the lights came closer to me.  I ran inside and called for my mom & dad and my younger brother who was 16 at that time.
 	For the next ten minutes we observed the lights as they came down to about tree top level.  They would float back and forth, moving perhaps 10 yards at a time.  Then they slowly moved from the back of out house to the front.  They paused over some trees at the corner of the yard and then slowly moved out over the town toward the north.  We watched them until they were out of sight.  There was no sound that we could hear and we could not make out any form or object, just the lights.
 	We did not see the half moon lights after the floating lights left.