Triangle shaped object traveling east to west approximately 45 degrees above northern horizon.While observing an unusually strong display of aurora borealis I noticed an object traveling from east to west approximately 45 degrees above the northern horizon. This object traveled across approximately 90 degrees of visible sky before I lost it behind ground clutter. The best description I can give would be a plastic coat hanger with the hook at the top removed, leaving a flattened triangle with rounded corners. It appeared to be either clear like acrylic with many small lights inside, or perhaps a light gray that matched the background sky color with a highly reflective surface in which case the many small lights may have been reflections of ground lights. I have been an aviation buff for most of my life and this was no aircraft I have ever seen. While the shape was reminiscient of a hanglider there was no "swooping motion" typical of "kites". Since there was no sound it couldn't have been an ultralight either,they use very noisy small engines and this was silent. The movement was straight and level so must have been powered flight. the size at arm length appeared to be about three inches wingtip to wingtip and about one inch nose to tail. While I can't say the exact distance from me I have the impression this was about the size of a small private aircraft which would give it an altitude of a few hundred feet, certainly low enough to hear engines or see someone hanging below a hanglider. Speed would be hard to estimate, but it only took five or six seconds to cross my line of sight, much faster than any private plane.((NUFORC Note: Date is approximate. Satellites generally do not have a westerly component to their orbit, and they do not move across the sky as dramatically rapidly as the witness indicates here. PD))