Close observation of hovering saucer shaped craft about 75' above the ground.

I was 10 years old in 1967.  My parents weren't home and my bbrothers and sisters were playing around the house.  I looked out my parent's bedroom window and saw the craft hovering about 75ft. above our back yard.  It completely filled the sky above our yard.  It was silent.  I ran to the back door and yelled to my brothers and sisters that there was a UFO over the back yard.  My two brothers aged 8 and 9 and my older sister almost 13 stood at the back door and watched it for some time.  We could see lights and windows with beings inside.  I don't remember anything beyond shadowy forms.  I don't know how long we watched it for, but eventually it slowly hovered down our back alley until it got to the end of the block, which was the edge of the city at that time.  It then accelerated at an incredible rate upward and to the N.E. and dissappeared in a couple of seconds.
The next day I noticed that I had scabs about the size of the end of a pencil on both shins I could not explain.