On december 07 at 5:15 pm i went outside at work to have a cigarette. it was a clear day and the sun was just going down and it was close to civil twilight. i noticed a bunched of planes in the sky and then spotted a larger, brighter light just above the horizon. i quickly grabbed my phone and started recording as i realized this object seemed a bit strange and was unlike anything i have seen in the sky before. it was pulsing or strobing in a weird manner and it didn't seem like a spinning satellite. i watched it for a few minutes and tracked it as it moved in a straight line heading northwest over my head. i observed and filmed this pulsing object for about six minutes and watched it slowly travel on a straight trajectory heading north west above me. i looked at other planes in the sky nearby and compared it to what i was watching. on the planes in the sky you could just barely see the red and green strobe lights and you could see the plane body still lit up by the existing daylight. at first i accepted the possibility that it was an aircraft heading straight towards me with the landing lights or collision lights on. but then noticed it was constantly pulsing, moving very slowly upwards, almost stationary. this bright pulsing light had no visible colored lights. there were no navigation lights. i also thought this bright pulsing object was a satellite or maybe the iss, but it was only 5:16 pm and in the stage civil twilight, it was still not dark enough to see any stars. after watching the video over a couple of times i noticed a peculiar movement as it got over head and thought that the strobing frequency changed but couldn't really calculate it accurately. at about 30 seconds in, on the second video the light seems to change its speed and direction. judging the distance from the electrical cord hanging down from the eave-trough of the roof that is visible in the second video, you can see that the pulsing object appears to slow down, and then dives down to the left, and then zips back down to the right, and then zips up to the left on its former trajectory. i later stabilized the shaky camera footage and the zig zag movement becomes very clear. i could not see the object clearly at all times while filming the second video as it was over head. it was heading into some cloud cover and just pointed the phone camera at where i saw it last. it seemed to be completely behind some clouds so i stopped filming. the videos can be seen on youtube here= part one – https://www.Youtube.Com/watch?V=x_rbqmwm02m part two – https://www.Youtube.Com/watch?V=kppfiipsnsu part three- stabilized footage https://www.Youtube.Com/watch?V=_az3virx6iu