2 solid red lights in flying formation fly from east to west.

2 red lights seen moving in perfect formation from east sky to west sky.  Looked like helicopters in formation but moved very slow with out noise.  Jets we seen flying above.  Separation of lights was approximately 1500ft.  
Sparks-like material dropped from trailing light in Western sky then light went out.  Second light stayed on for another minute then was turned off.   
Went back on for 30 seconds then disappeared.  
Was not a planet as those can be seen in picture.
See similar reports from Tinley Park, IL, for August 21, 2004, and October 31, 2004.  PD