This afternoon I was in my backyard in North East Portland and heard a loud helicopter approaching. I looked up and immediately caught sight of something moving very fast in front of the sky that my eyes locked in before finding the helicopter. It was a small white dot, very high up in the sky, traveling from SW to NE at an incredible speed. It had to be the fastest thing I've ever seen moving in the sky. Then I realized the helicopter was following it, much slower and lower. And it was defin...