there was a light that lasted for 2 to 3 second maximum and it was gone over the horizon.there was only one object. It was heading due north above us on highway 400. the object was a bright white light and traveling horizonally northward with the earth.From the time of sighting overhead it was gone over the horrizon within 2 to 3 seconds. this was with a wide open sky. no clouds in front of us and stars in the sky. whatever we say we saw it at the same time and before we could say "what was that " it was over the horizon. There are no aircraft or even comets that I have heard of like this. I have seen fighter jets going as fast as they could go before and you could still follow them for a while. there was also no sonic boom or anything. I can not figure out what this object was. I used to work at the airport and have never seen anything like this before.