UFO Sighting in Fallbrook, California on 2015-08-19 21:15:00 – Half circle green light appeared hovering, illuminated. yet not not projected light from or to the ground. object changed shape to lava like orb then

Object was green, appeared under 5000 ft.It was half circle and morphed into full circle and was the color green similar to antifreeze. this did not make a sound or illuminate the ground. there was a full moon and it appeared to be the same exact size as moon after morphing. then it shot with a spiral like rifle bullet at what could only be described as mach27. within 2 seconds it's in another galaxy. it made no sound at all from stationary to morphing to mach 27. there were two witnesses that saw the event. having completed astronomy 101 and seeing satellites, rockets, meteorites and a fireball in yosemite it was none of those.At no time was there noise or a propellant trail. when it morphed it moved south and when it accelerated it went to the stars.