Ok, so I was playing a game of halo reach in my living room. My couch is perpendicular to a patio door facing east. I live on the last floor of my four story apartment building. I have a pretty good view of the sky, but there's many other same size apartment blocking it. Lets say that about half of my field of view is blocked. I can't recall the exact time but I know that the sun wasn't down yet. It was around 5:50 pm (the sun went down at 6:03 pm here on that day). The weather is a clear blue sky with a bit of cloud, but mostly on the horizon.So there I am, relaxing after school, playing a bit of halo and speaking with buddies on my microphone. In between two games, I turn my head toward my windowed door, and I see this star-like white with a very faint blue/purple toward the outline on the top of farthest building. If I can compared the color of it to something I know, I could say that it looked like magnesium burning. For its initial position, if east is noon, and the limit of my field of view is 9 o'clock on my left and 4 o'clock on my right, it was approximately at 11 o'clock. Seamed bigger and brighter than your regular stars. When I see things in the sky that I'm not to sure of, I try to look at it and a inert object (the white frame of my door in this case) and stay still, to determine if it's moving or not. My conclusion at that time: I'm looking at a UFO slowly moving north (toward 4 o'clock). A bit exited about this, I get up, open my door and take my head a bit outside to see the stars I normally see at this hour are there. Everything seams to be in place. So after I opened the door, look at the sky and look back at the object and I see that it's still bright but slowly dimming and accelerating. No erratic movement up and down, it's simply staying at the same altitude and traveling in a linear fashion toward north. I didn't get the feeling it was getting closer or farther of me. At the moment the light dimmed to about half of the initial size, I start to see a flashing light behind it. It seamed like the initial light was the headlight of the UFO and this new flashing light was the tail light. The head light had the same initial color (less brighter) and the tail light was white. The tail light blinked a bit like a normal airplane, but the frequency was a bit wrong. I couldn't make out any solid in between the lights This flashing tail light really confused me. I said, at that time, to my buddy: "It's maybe a airplane" and he's like "yeah your right you were overreacting at first, it's a plane"... Of course he was skeptical. I could say that the rest of the sighting was it simply going is way, accelerating and still dimming its light (like if it was going through a cloud, but there's no cloud) until I lost sight of it behind a building. The final position of the object was about 10 o'clock, using the clock system I described earlier. The overall speed of this UFO was a bit slower than airplane at first, but was definitely faster than a conventional airplane at the end. After the sighting, I said to my buddy: "Yeah maybe it's a top secret military airplane, but I never saw a airplane with headlights this bright"... Now, when I think about it, there's no ambiguity, it was a UFO (extraterrestrial or not).This sighting hasn't surprised me. Disclosure is near. This isn't my first encounter with UFO, but it's my first sighting report to MUFON. Why bother submitting it? Because I think that October 13 2010 was a special day.