The Astronomical Almanac is a book published each year by the United States Naval Observatory and Her Majesty's Nautical Almanac Office. It includes information on astronomy such as the setting and rising times of the sun, moon, planets and stars, as well as eclipses. It has been published since 1767. In 1981 the American and British publications were combined. The information in the almanac is used by astronomers, navigators, surveyors and space scientists. Using the information it would be possible to work out your position on Earth to within 500 metres.