I was driving home from work, heading West on W Airport Frwy (in Fort Worth, toward downtown) at approximately 9:40 pm on Thursday, Dec 13, 2012. I had the windows up and the radio on so I did not hear any sound, however, the object was solid, round and glowing a beautiful cobalt blue. It came from the direction of East (behind me) and I saw it out of the left side of my windshield for about 3 seconds, and then it suddenly disappeared. It did not seem to land, just vanished in mid air. There were no buildings close enough for it to have been hidden by. If I had to guess, I would say it was likely about a mile up in the air. I have never seen anything like it and there was only one (that I personally saw).It flew in a slightly angled path just before it disappeared. My reaction was to try to rationalize what it could be, but I came up empty. This was not any known aircraft (none that I am aware of). There were other cars driving the same route, both ahead of and behind me, and I am wondering if any of them saw the same thing.When I first saw it I simply had no clue what it was, my first reaction was simply that it WAS, simply put, a UFO,