Metallic cylinder shape object zig-zagging across sky at a very high rate of speed.

This description came from my mother and sister who actually saw it. According to them, they were out on their daily morning walk. When they saw this object that was zig-zagging across the morning sky at a very high rate of speed. They claim that it only took it a few seconds to do so. Then it turned and came back at a much slower rate of speed, where they could see it had just one white light and a red one. Then it went behind a small cloud and disappear, never reappearing. They stood there looking for it for another few minutes before finishing their walk.