At approximately 6:30 pm I was at my home near SR56 facing north and I was about to walk into my garage when I noticed what I thought was an airplane of chopper in the sky traveling east to west, about 50 - 60 degrees off the horizon, which is where I usually see planes in the TPA flight path. I thought it was odd because unlike the other planes, this one had no strobe lights or colored lights, it was the color of a flare. I thought it might be the ISS, but the time I saw that it was white reflecting the Sun and traveling west to east. It looked very much like a meteor except if it was then it was very high up because its apparent speed was like that of an aircraft. I thought it might be a missile being launched from the east coast of Florida, but it was further north than the space shuttles I've seen launching almost due east from my location. Since it looked like it was near the airport's approach path I thought it might be a SAM except that it flew in a straight line and did not waver. I kept watching it for about 30 seconds until it either went behind a cloud in the west, burnt out, or turned off. The brightness of the object did not vary at all and nothing fell off of it.