Large extremely slow moving craft with red and white lights makes several low altitude passes over Rockford.A large chevron shaped aircraft passed slowly by at speeds too low for a winged craft and there were no rotor noises. The craft flew at an altitude of approximately 200-300 feet and had a jet engine sound but with a much lower amplitutude than a commercial or military jet. There were 2 lights pointing in the direction of flight, and the lights were inbound from the tips of the wing. There were 2 red lights flashing/pulsating on each side of the craft. The craft flew past about 100 feet in front of us and we watched it until it was lost in the horizon or tree tops. The craft circled around and made similar passes at least 5 times. It was cloudy and slightly foggy so it was impossible to make out any detail of the craft due to the diffusion or glare caused by its onboard lighting. I have seen the V-22 Osprey and this was definitely not one of them or any type of jet airplane that can hover or fly at low speeds that I've ever seen. It flew nearly overhead and h! ad absolutely no propellor or rotor noise. It sounded like a turbine driven craft. During the last pass we heard a few smaller higher pitched turbine sounds emanating from the craft which sounded similar to mechanical adjustments being made, similar to when a jetliner sets it flaps. My estimate is that the size of the craft was in the neighborhood of 150 ft long by 200-250 ft wide, and the body/fuselage appeard to be somewhat bulky as if it could carry large cargo. We did manage to take pictures and will transfer them to the PC in the morning. My impression was that the craft was military and not extraterrestrial. I am a skydiver having over 100 jumps, including 2 jumps from a Boeing 727 jetliner, in addition to attending many Air Shows over the years as an aviation enthusiast. I also studied to become a private pilot and am very familiar with the many types of aircraft, the speeds at which they can fly, and their sound characteristics. This was like nothing I had ever seen or heard and the other 2 witnesses have the same opinion.