I went outside at work to have a cigarette and noticed a star next to the moon and thought how weird it was that this was the only visible star in the sky and how bright it was. Then as I stared around at the sky to try to see other stars (which I finally noticed a few dim stars), I saw 2 glowing shapes flying across the sky at super speed, but very low to the ground. It wasn't lights but more of a luminescent glow that was very dim. There was nothing flashing, no blinking lights, just the 2 glows. I couldn't really tell any shapes of a spacecraft, only the glow. They were going very close to the ground, maybe 30-50 feet up. As they passed above me, they crossed each other like they were swapping places...right glow to the left, left glow to the right, and just speed off across the sky. They were absolutly silent as I remember hearing nothing but the grass crunching under my feet as I stared at them in awe. I've seen hundreds of airplanes cross the sky where I was, and have never seen anything that you couldn't tell was a plane by the blinking colored lights and visual shape of the plane. Not to mention it was far to close to the ground. I was very scared, heart pounding at what I was actually witnessing, but I had watch it and follow it until I could not see them any longer because I knew it was such an extraordinary event. After they flew so far away I could no longer see them, I got very paranoid and started looking at the clock to make sure no odd/missing time had passed. I just sat in utter awe and shock afterwards. I just could not believe what I had just seen.