three white patches forming a dim triangle (looked like one craft) flying completely silently, low, and at constant speed (fast) North.Low-flying, completely silent, three rectanglish maybe triangular white patches in night sky (not bright and shiny, but pale and somewhat luminous) formed a larger triangle shape. The "point" or "tip" pf the triangle leading north.At first we thought it was three birds. But there was no movement expect the unwavering steady fast paced movement forward. constant speed and seperation of white patches soon made it obvious it was no animal. It looked as if it was low-flying, much lower than the average plane, yet it was silent.If it was extremely high up, then it would have been extremely massive, beyond anything we know today in modern aviation.As if to prove it was no ordinary plane, a moment or two after it passed (it was moving quite fast, and I must stress again, completely silent) a regular passenger jet plane flew overhead, (with a trajectory slightly deviated from the first unidentified craft) it was very, very high but we could still hear the jets, loud and clear, the lights on the bottom of the plane twinkled and shone and blinked. There were patches of fog so this jet had headlights that illuminated the clouds in front of it.The first craft had no such headlights, nor any standard lights on the bottom at all. The white patches which formed the triangle did glow, as if emmitting heat, but where not shiny, there was no tendrils of light from them as there are from normal plane lights or even far away stars etc. IT was a subdued paleness that stood out against the night sky, faint, but there never the less.The two white patches that formed the "base" of the triangle were set farther back than the lights on the wings of the jet that followed soon after.