Thirty red-orange lights in the sky - south to north over Skippack.About 30 red-orange lights (looking like helicopters flying south to north). A parade, one right after the other. Absolutely no sound - so they could not have been helicopters. It took about 20 minutes for all 30 to go marching north. They seemed to be following route #113 (from the Perkiomen Valley Airport north to the PA State Police Office in Skippack, PA.