Small white very fast moving object over Cape TownIt was 18:40 South African time and I was looking up at the sky and saw an object travelling very fast in an exact straight line almost like it was on a fixed track.I mentioned it to someone and they said it could have been a drone but i doubt it, it was too fast and no "publicly available" drone as far as I know travels in a perfectly straight line.It could have been a shooting star but it was an unusually long duration and it brightness never changed which is the norm (again as far as i know). There could well be some rational explanation but all I know if I've never seen anything like that.