http://www.youtube.com/watch?v=6Mz1E9fKA48
All I have for you is a simulation. This thing I saw was NOT a passenger plane. For one thing it was too big, but more than that, it was low to the horizon. For it to be a plane, considering the angle, it would have had to have been in a nosedive or climbing almost straight up. It was low above the horizon when I saw it, and I could not have seen the underbelly of a plane in this fashion uness it was headed either straight up or down. It could not have been a blimp, pyrotechnics or any of the usual explanations.