On a sunny day in June 2002, this grey disc-shaped object appeared over the port of Antwerp, Belgium. It's diameter was at least 10 metres (32 feet). The story is completely true, but there is a catch.

Hover the cursor over the image to find out that the disc is real. It was part of a temporary structure built to comemorate the 20th Anniversary of the local Chambre of Commerce and Industry (Kamer van Koophandel en Nijverheid Antwerpen-Waasland). It's stylized shape refers to the Middle Ages, when wooden towers were erected alongside the quays of Antwerp to spot incoming merchant ships. The supporting structure beneath the disc was erased using a digital clone stamp, a much used PhotoShop tool.

[© Wim VAN UTRECHT/CAELESTIA. Image-over script by Chris POOLE]