Was driving on 495 before sunset, around 6PM, I was looking out the windshield on the drivers side heading toward Worcester when I noticed a circular object in the sky. For a moment I saw it, then just like that, the thing moved faster than any airplane or jet across the sky then it disappeared from my view through the windshield within a blink of an eye, photo fast. That thing was gone within the snap of my fingers, no time to reach for a recording device, it's like it noticed me notice it.