I was walking my dog about an hour after midnight, when looked to the skies I noticed this formation of about five lights. It was a quiet night, no wind, no clouds. The part of the city I live is very peaceful, but I was not able to hear any sound from this formation. When I first noticed it they were to my left, in direction of South-West. At first, I thought it is just my imagination, but as I looked at it moving across the night sky I realized it is real. Light were kind of blurry, as when you would see a car head lights in the fog (but there was no fog or clouds on this particular night). As I starred they just vanished. Would like to note that no airport is in that direction, and that commercial planes do not fly over my town in that direction. Would also like to point that I haven't seen any object, only those lights flying silently in a triangular formation.