What kind of aircraft has 3 lights in a triangle?

I saw something tonight on my way home, and I don't want to be like "OMGEE GUYZ I TINK I SAW AN UFO!!" Lol it just creeped me out, because I've never seen anything like that. It looked like 3 white lights in a triangle form. There were no blinking red lights like there are on planes. And the thing looked like it was sitting still at first, but I noticed it was moving slow a few seconds later. What kind of aircraft is like that? I don't want to jump to conclusions, so that's why I ask. =)