A series of red light flew overhead

July 2, 2011. Santa Fe, TX.  At about 10:00pm I was in my front yard,  I looked up and directly overhead were four bright red lights.  Very pretty,  I went in and called my wife to come out and look.  We watched as they slowly moved off toward the northeast.  Then we looked  back and four more red lights were over us.  They were not flashing of rotating.  The night was clear and starry and the red lights were low enough to be seen very clearly.  They flew away in single file following the first lights.  Then we looked back and four more red lights were coming overhead, they were slightly north of the first lights but going in the same general direction.  No noise, moving slow, and we watched until they went out of sight.  They seemed to be getting higher as they flew away.
I am 73 years old, a retired firefighter, arson investigator and I flew airplanes for 30 years.  I am well aware of what aircraft lights look like and these lights were not any kind of aircraft that I have ever heard of.  They were too far apart to be a single aircraft or three large aircraft.  They were just individual lights following each other across the sky.  I would really like to know what they were.  This has been on my mine a great deal and I have no answer.  Maybe you can tell me what this was.
I talked to other people in my neighborhood who said that they say the lights also.