I had to go out to my car at 11pm. my car was parked in a lot just inside the sand dunes with the atlantic ocean 200 or 300 ft away. i observed something in the sky over the ocean... i kept watching and realized it was not a plane. it was a narrow verticle column of lights, blinking green and red... alternating (what blinked green then blinked red and visa versa). it stayed still for the 20 minutes or so i watched and then i went back inside. i would say it was at least a mile away and 20degrees above the horizon... it was in the air, very clear cloudless night sky. if it was a mile away i'd guess it was 200 to 300 feet tall... if it was farther then it was bigger........ the best way to describe it would be if you had a double column of colored spotlights attached to a telephone pole and the lights were as close to each other as possible and each light would blink green and then red and ten green again. i took a photo with my cell phone but it was so far away you can only make out that there are lights in a short verticle column (not as tall, not as many lights as i saw)... the colors did not resolve so it just looks white/offwhite and does not represent what i was seeing.