I had a dream very similar to that one, but interestingly I had it several years back. I remember looking outside my parents home and it was in the middle of the night. I some how just intuitively knew it was "the end" of my life and possibly the world. I went outside and looked to the west and saw a bright sunny light like the sun, light up the western sky like it was broad daylight but was the middle of the night. The sphere light was rapidly descending but was already near the western horizon. It was obviously a large comet or meteor. Before it hit the earth, I woke up. That is the gist of the dream in what I could remember. I would say that I had that dream about 7-10 years ago. So when you mentioned this dream, I was shocked.