Observed large dark object, triangular in shape, with three white lights at each point, and one blinking red light center, come silently from the west and glide over us turning north. object was last observed turning nw before disappearing behind trees. time approx. 2030 at night. duration approximately 7-10 min. sky was dark and clear with visible stars. no moon. object was seen at approx. 35-40 degrees from horizon, appeared above 500ft., and moved quickly without sound. object appeared very large. nh national guard helicopters seen low under 500ft altitude before and after sighting. witnessed by myself and my wife 09/09/2020 in concord, nh.