Huge!I was outside this evening,admiring the Milkyway as it is a really clear night and I live in the country.I was staring at one spot and noticed something start to move in my peripheral.A "constellation" of three stars forming an isoceles triangle about the size of a dollar bill held at arms legnth was moving slowly from North to South.It took approximately 30 sec to disappear behind south horizon from the time I first noticed it,directly overhead.From my days of sattelite watching,I could tell that it was not in the atmosphere.The three lights were as dim as the dimmest stars and hard to see at times.It also seems to me that it was blacking out stars because I was left with the impression that it was solid. I spoke to someone at the Reporting Center just minutes ago,and he informed me that what I most likely saw was a formation of sattelites.This seems logical,I just can't get over two things;I swear that they were not moving initially,and the blacking out of stars(there is a barn with a light on it to the south,about 30 yards away,so as it prgressed that direction it bacame harder to see which is why I cant swear to the blacking out). I'm still pretty shook up,though the man I spoke to did give me a reasonable explanation.