At first the five of us thought it was some kind of a firework display as the fireworks in our area were wrapping up. We were outside cleaning up after shooting off fireworks. This orange glowing orb was first observed in the north over the subdivision across Brownsferry Road moving south in a straight line towards us. It traveled over a tree line and then took a hard turn west and then disappeared. Not sure if it accelerated or vanished. This object was glowing orange with almost a white edge. The glowing effect kept us from seeing any hard edge. We all thought it was fireworks at first or even a military drone (I live very near Redstone Arsenal and MSFC)as it travels closer we knew it wasn't a plane, it was way too low. There was no sound st all and this thing was very close to us.......My Aerospace Engineer boyfriend calculated that it traveled 3 miles in about 10-15 seconds. We've seen drones and they didn't look anything like this! We had a camera and the batteries were drained when we went to shoot a photo.Too me it looked almost like a plasma ball as it undulated orange white and little bit of red.