Green triangle craft dropped out the sky and dissappeared.I was driving down Interstate 35 about two or three minutes south of the Story City exit, when I looked to the west and saw a bright green craft rapidly moving. It appeared to be a triangle shaped craft. It left a blurred-looking trail. It was low in the sky and large. It seeminly dissappeared after five seconds. I saw a similar looking craft last year at about this same time of the year only an hour south of where I saw it tonight. It seemingly dropped out of the sky and then dissappeared. It did not fly over the horizon just was there moving fast and then gone. I am a senior in college and am a military cadet less than a year away from receiving a commission as an officer. I know military craft and this was nothing acknowledged by any government on Earth.