Lying on the dock of the Neckar River in Heidelberg, Germany, on the Neuenheim side, I was watching the sky, waiting for a friend. There were a few planes going around. It was a clear night, and bit cold. Out of nowhere I then noticed this thing. I didn't know what it was when I first saw it. I call it a "thing" because the 5 aspirin-sized lights were moving completely together, evenly spaced, and gave no impression that they were separate objects. They were in a V formation, heading west. The circles of light were not very bright. They almost looked a bit "foggy". They were whitish leaning towards grey (I think because of the foggy effect). There was no other detectable shape behind them (e.g. a wing). As I had been watching the planes before I'd seen the lights, it had seemed a completely clear night. This thing, however, seemed to be going through thin clouds periodically. I say thin because the lights were never completely obstructed, as if the clouds were translucent. It was also moving WAY (4x? 5x? 6x?) faster than the planes in the area.I thought the object might be: 1. very high up because it went through clouds that the planes in the area did not, and2. very, very large because of the size of the lights and the inferred altitude.I watched it for approximately 15-30 seconds before it moved out of my range of sight.While watching it I felt transfixed with wonder. Ever since then I've been trying to find out what it was.Any help would be appreciated.