UFO Sighting in Knoxville, Tennessee on June 12th 2015 – cylintrical object flying NE when it pulsated a white glow twice. Had a dark line in middle of object

Was out watering flowers when I looked up and noticed a cylinder shaped object (again) that caught my attention. After watching it it changed from silver looking to glowing very bright white on both ends. It did this twice while I was observing it. The actual front of this object lit up first followed by the end lighting up. The dark strip in the middle of it did not glow and remained very dark. The second time it "glowed" both ends illuminated at the same time. I am saying again because I saw and reported another cylindrical object looking the same as this one a few years back. As a matter of fact I think that the direction was the same as before. That first sighting did not have the object glowing though. I am really "confused" because for some unknown reason I keep forgetting to report this sighting. I am always looking up and very interested in these things. I made sure this "glowing" could not have been from the sun setting. The sun was already at the horizon and could have in no way been making the object appear to glow from the sun reflecting off of it. The color changed to very bright white light dimmed and lit up again. I did not have time to run into the house to retrieve a camera. It was out of my sight in about 10-15 seconds. A plane at this altitude would have taken much longer to go that distance so I'm reporting that it was going very fast. It was be about an inch long and was about the same elevation as planes.