Large Black Triangle with three Red Lights at each corner about 500 Meters big flew at about 100Feet!!!!

I live right near busy Manchester international Airport.
 I was just stood outside my house with a friend and it was quite a clear night at about 9pm.
 Suddenly a massive black triangle about 500 meters across with thre small dull red light at each corner i think the tringle was quite pointed and not equalateral.
 It made no noise as it flew/glided about 200feet and went right over the houses in full view of everyone i didnt see any markings at first i thought it was a plane but it made no noise and flew really low.  I saw it for about 8 seconds before it either diasappeared or flew away really fast plus it kind of caqme from out of nowhere  I am really worried becuase it seems as though they only let certain people see them??  Some people say they abduct you and you dont even know it  SCARY