A nautical almanac is a publication describing the positions and movements of celestial bodies, including the sun, moon, planets, and 57 stars chosen for their ease of identification and wide spacing. The Almanac specifies for each whole hour of the year the position on the Earth's surface at which each body is directly overhead. The Sun, Moon and Planets 'move' independently and so are specified separately, but for the stars only Aries is specified, the other stars having a set angular distance from that. The navigator can extrapolate by means of difference tables to obtain the position of each object for each minute of time. The Sun is the star at the center of the Solar System. ... Apparent magnitude: up to -12. ... The eight planets and three dwarf planets of the Solar System. ... This article is about the astronomical object. ... Aries (IPA: , Latin: , symbol , ) is one of the constellations of the zodiac. ...

In Great Britain a nautical almanac has been published annually by the HM Nautical Almanac Office, ever since the first edition was published in 1767. The HM Nautical Almanac Office (HMNAO), now part of the Rutherford Appleton Laboratory, near Abingdon in Oxfordshire, was established in 1832 on the site of the Royal Greenwich Observatory, where the Nautical Almanac had been published since 1767. ... 1767 was a common year starting on Thursday (see link for calendar). ...

Also commercial almanacs were produced that combined other information. A good example would be Brown's - which commenced in 1877 - and is still produced annually, its early twentieth century subtitle being "Harbour and Dock Guide and Advertiser and Daily Tide Tables". This combination of trade advertising, and information "by permission... of the Hydrographic Department of the Admiralty" provided a useful compendium of information. More recent editions have kept up with the changes in technology - the 1924 edition for instance had extensive advertisements for coaling stations.

The "Air Almanac" of the United States and Great Britain tabulates celestial coordinates for 10 minute intervals. The Sokkia Corporation's annual "Celestial Observation Handbook and Ephemeris" tabulates daily celestial coordinates (to a tenth of an arcsecond) for the Sun and nine stars.

To find the position of a ship or aircraft by celestial navigation, the navigator uses a sextant to take a 'sight' to measure the apparent height of the object above the horizon, and notes the time from a chronometer. The object's position is then looked up in the Nautical Almanac for that particular time and after allowance for refraction, instrument error and other errors, a position circle on the Earth's surface is calculated. Celestial Navigation is the 15th episode of The West Wing. ... A sextant is a measuring instrument generally used to measure the angle of elevation of a celestial object above the horizon. ... A chronometer is a timekeeper precise enough to be used as a portable time standard, usually in order to determine longitude by means of celestial navigation. ...

Nautical Almanac is also the name of an important Avant-garde noise band based out of Baltimore, MD, featuring Carly Ptak and Twig Harper. In 2004 they released the album "Rooting for the Microbes" on Load Records.

See also

• Celestial navigation
• Navigation

Celestial Navigation is the 15th episode of The West Wing. ... Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia. ...

External links

• Her Majesty's Nautical Almanac Office
• The History of HM Nautical Almanac Office