The object was ring-shaped, bright, white in colour and moved silently behind the sparcely clouded sky, bearing West to NorthwestThe object first appeared as bright (white) pencil shape (some spots were brighter than others along the pencil shape). The object then appeared to alter its shape to an elongated oval, then finally to a perfect circle (the circle seemed empty !!). It moved from 20 degrees above the Western sky, behind a sparcely clouded sky as it's shape changed from a pencil shape to a perfect ring (bright white at all time), towards the Northwest, then dissapeared behind a cloud. This siting was during North Bay's annual Air Show (on the shore of lake Nippissing), which I attended for the first time, as a visitor. I was accompanied by my 22 year old step-son. I, myself, am 59 year old. As my step son and I pointed to the object in amazement, others in the crowd also turned towards the object and witnessed it. When it finally dissapeared behind a cloud, everybody's attention turned toward the ongoing bi-plane acrobatics.