We saw a never explained dark large triangular object, hanging still and silently in the night sky over our backyard.

Three pre-teen boys and their older sister were the witnesses. 
The boys tumbled into the house from playing, white as sheets, and the two younger prodded the oldest to talk to me the "big sister" babysitting for the evening.  I listened impatiently as the oldest stuttered out that there was something HUGE up in the sky blocking the stars and it was a triangle and it wasn't high up but it wasn't low either and there were stars all around it and it WASN'T MAKING ANY NOISE and ended with, "we're scaaared!".  (I'm not sure if I remember he noticed lights or not).
I laughed and said I would check it out and they pleaded with me not to, but I told them mom and dad wouldn't believe us unless I saw it, too.  
I looked outside and up and it was exactly as he said.  A big black triangular void with no noise and no movement and no emissions, yet stars all around it.  I also noticed a complete absence of bugs, birds or pets making any noise and that's when I really creeped out and fear overcame my curiosity and I backed into the house slowly, keeping my eye on the unknown object. 
It seemed like it was no more than a couple of hundred feet up which would mean I should be able to hear something!  
My parents thought we made it all up of course and suggested it might be a weather balloon or experimental aircraft from Bush Field Airport or Fort Gordon Military Base.  I never believed that.  
When I saw the stealth bomber years later it reminded me of it, although this had what appeared to be equal angles (equilateral) but again, there was no noise, no movement, and no emissions.  Just a big black triangular void that was definitely a solid object silently hanging in the air.  I don't remember seeing lights, but my brothers might, I'm going to ask them when I get a chance.
Witness indicates that the date of the sighting is approximate.  PD