2003-10-26 - Bristol (UK/England) - Other

Okay, this is a new one on me, maybe someone else has seen these too. Towards the end of October 2003, around 9:30 pm with a clear sky, i saw something which looked like an m flying north at speed. It was dark grey in colour, no lights and no sound not even when it passed almost overhead at around 4000ft at a guess. About a week later i seen another one, around 11:15 pm, cloudy and dry, light winds. This one was flying south but had three arches, this too showing no light or making any sound as it passed overhead. I knew the height was around 4000ft as the aircraft from the local airport turn at 3000ft on to their new headings, and a minute later were going in to cloud which put them at around 4000ft+- This one however was reflecting the glow of the town lights making it stand out against the clouds above it, and was about the size of a 737 and again, traveling at a fast speed which i couldn't even guess at, except to say it was out of sight in roughly three seconds max, my view being vertical ish an down to the horizon. Since then i have seen another twin arch again in early December around 1:am, clear sky and flying northeast, as before, dark grey, unlit, silent and fast.