Child remembers seeing object over 40 years

I was 4 or 5 years old, we lived somewhere in columbus ohio.  My sister and i shared a room and we had bunk beds, mine was athe top postioned right next to the window. 
I awoke one night to see a cigar shaped cylinder moving in an irregular pattern, occasionaly hovering, there seemed to be faint green glow to the object and there was some sort of glowing entrail, it appeared to be just over my back yard.  It was beautiful, but I remember being frightened. 
I yelled for my mother but by the time she came into the room, it rose into the sky and had left. No one believed me. 
The next day I found an odd rock in the yard that for some reason I have carried with me to this day, throughout many moves, throuough many states. 
I can still see the image in my mind over 40 years later.
Witness indicates that the date of the event is approximate.  Witness elects to remain totally anonymous, and provides no contact information.  PD