Omega SA is a Swiss luxury watchmaker based in Biel/Bienne, Switzerland. Omega is one of the most well-known and recognized watches in the world. Omega watch was the choice of NASA and the first watch on the Moon in 1969. Omega was the official timekeeping device of the Olympic Games. James Bond has worn it in films since 1995; other famous Omega wearers are John F. Kennedy, Prince William, Buzz Aldrin, Joe Biden, George Clooney, Nicole Kidman, Michael Phelps, Zhang Ziyi, Stephen Colbert and Cindy Crawford. Omega estimates that seven out of every ten people have heard of Omega watches. Omega is owned by the Swatch Group. The selection of the "Omega Speedmaster Professional Chronograph" for American astronauts was the subject of a rivalry between Omega and Bulova. All subsequent manned NASA missions also used this handwound wristwatch. NASA started selecting the chronograph in the early 60s and automatic chronograph wristwatches were not available until 1969. However all the instrument panel clocks and time-keeping mechanisms in the spacecraft on those space missions were Bulova Accutrons with tuning fork movements,[citation needed] because at the time NASA did not know how well a mechanical movement would work in zero gravity. The "Omega Speedmaster Professional Chronograph" was the first watch on the moon, worn by Neil Armstrong and Buzz Aldrin. Armstrong's watch is now displayed at the National Air and Space Museum in Washington D.C. Aldrin's is believed lost. He mentions in his book, Return to Earth, that when donating several items to the Smithsonian Institution, his Omega was one of the few things that was stolen from his personal effects. In 2007, to mark the 50th anniversary of the Omega Speedmaster Professional Chronograph, the Omega company unveiled the commemorative Speedmaster Professional Chronograph Moonwatch. The watch had the distinctive features of the first hand-winding Omega Speedmaster introduced in 1957. It was sold in an edition of 5,957.