Several years ago, my husband and I was setting out on the back porch under a awning on a swing, late night. The object appeared from the North east at a high rate of speed. There was a floresent electracil light from the back of the object and there was no sound other than a swish.

It came to a complete stand still over our back yard and we were surprised.  The object was triangle in shape and the green light slowly went out and a floresent white light was across the front.  
After looking at it for a few minutes and wondering what it was I stood up.  
You could see it rock back and forth but still no sound.  Shortly after I stood up the lights went out just like someone turned them off.  It still stayed over our back yard for a few more minutes then we heard another swish and it took off really fast.  
It went north west toward Goodfellow Air Force Base.  I do not know how it could stay still up there without falling other than the rocking motion, might have had someting to do with it.  I am still wondering what it could have been.  
It was dark so I could not tell what the bottom of it looked like, only the outline of it.  
We both didn't think anyone would believe this so I told only family up to this point. Not easy to put in a summary.
Witness indicates that the date of the incident is approximate.  PD