A bright light was visible in the sky on Tuesday night after the Perseid meteor shower, causing confusion among viewers. The light was not a super-sized meteor or UFO but rather a Vulcan rocket launched by United Launch Alliance. The rocket took off from Cape Canaveral, Florida, at 9 p.m., carrying an experimental navigation satellite on behalf of the US military.
Source: https://6abc.com/post/ula-vulcan-rocket-spotted-skywatchers-philadelphia-region/17518953