A silver dot travelling straight down, became linear and flared white, disappeared

I was a travelling in a car, from parramatta toward wentworthville. We were stopped in heavy traffic. I saw a small silver dot, very high in the sky, travelling in a straight line down. It did this for approx 1 1/2 minutes. It then became very bright white, and elongated into a small linear line. It dropped a little bit more and disappeared. The sky was blue with some white clouds. The clouds didn’t obscure our vision. The sun was going down over blue mountains in far distance, it was lower than object by a long way.