While standing in a shopping center parking lot, myself and wife noticed a large fireball, initially impression was a hot air balloon size sphere combusting. But the fireball never burnt out, there was no smoke, contrail or sound. We then noticed a second fireball seemingly traveling adjacent to the first offset diagonally. Both objects traveled at approx 80 to 110 mph. Seemingly slower than typical helicopter in flight. The objects traveled in unison maintaining a constant distance from each other in a straight possibly slightly ascending flight but below a night overcast sky. The objects were observed below a dense cloud cover. Airplanes were observed in the sky at the same time as the objects but not in close proximity.