I was taking my trash out after dark. i like to look up at the night sky, the moon and the stars when i'm out. it's not uncommon to see planes or even a helicopter. what startled me was the shape which was triangular. there were three pulsating red lights on the edges. it just glided by, neither fast nor slow. it didn't travel a straight line but kind of went up a little and down a little. i craned by neck to watch it go by. i lost sight when it passed by my home. i did not follow because i was in my pijamas. i feel foolish now because i didn't run to get my phone but just watched confused, wondering what it was. i do not know what it was. it is unidentified in the truest sense. i know nothing about aircraft or astronomy. so, if this is something with a simple explanation i would really like to know. if this was something unique surely someone else saw it as well. i don't live in a large town but it's not exactly rual either. my neighborhood itself is fairly large.