Rapidly flashing green light in the west, moving steadily towards the northwest and gaining altitudeA green flashing light caught my attention in my peripheral vision. I discarded it as an airplane originally and didn’t pay too much attention to it. I didn’t even look at it at that point. Something didn’t seem right about it so once I sat down, I paid more attention to it. The light was flashing very rapidly and almost a twinkling type of flashing. It was not the typical flashing of an airplane or helicopter. It was very distinctly rapid (more rapid than an airplane or helicopter lights). I’ve never seen anything flash like that. The object seemed to be stationary at first. I stared at it and it still seemed to stay still. As I kept watching it I noticed the object was moving further away. I originally saw the light in the western sky and it was moving towards the northwest and was gaining altitude. I watched it until I couldn’t see it anymore.I couldn’t tell the shape of the object but my first instinct tells me it might have been a cylinder type shape, but I cannot say for sure. This was very strange and I have never seen anything like it.I did see an airplane shortly after (2 minutes or so) and it seemed to be heading in the same general direction, but did not appear to be chasing it. The plane seemed to be a coincidence and did not seem to be associated or even aware it was ahead of it.