I went outside of my work building to smoke a cigarette. i was looking in the sky because earlier i saw planes out spraying the sky. when i looked up i saw two planes one in the far distance and one closer to me. out of nowhere and i mean nowhere this round metallic looking object appeared and was flying as fast as the aircraft at about the same height. i thought it was a bird at first until i realized that you would not be able to see a bird that clearly that far up. this thing was almost as big as the plane it was flying near. then all of a sudden it excelarated in speed and shot past the plane and out of my sight. that is when one of my co workers came out and i told him what i saw. he did not believe me and still doesn't but i know what i saw. the sky was very clear and there were no other birds in sight. this thing was big enough for me to see that it was at least half the size of the airplane. i tried to get my phone out of my pocket and unlock it to get a video but by the time i did it was gone.