![]() In addition, observations between stars and other celestial bodies accomplished the same results whilst in space – and was used extensively in the Apollo space program and is still used on many contemporary satellites. The Moon, a planet, Polaris, or one of the 57 other navigational stars whose coordinates are tabulated in any of the published nautical almanac or air almanacs can also accomplish this same goal.Ĭelestial navigation accomplishes its purpose by use of angular measurements (sights) between celestial bodies and the visible horizon to locate one's position on the Earth, whether on land, in the air or at sea. This angular observation combined with knowing its simultaneous precise time referred to the time at the prime meridian directly renders a latitude and longitude fix at the time and place of the observation by simple mathematical reduction. Celestial navigation can also take advantage of measurements between celestial bodies without reference to the Earth horizon, such as when the Moon and other selected bodies are used in the practice called "lunars" or lunar distance method, used for determining precise time when time is unknown.Ĭelestial navigation by taking sights of the Sun and the horizon whilst on the surface of the Earth is commonly used, providing various methods of determining position, one of which is the popular and simple method called "noon sight navigation"-being a single observation of the exact altitude of the Sun and the exact time of that altitude (known as "local noon")-the highest point of the Sun above the horizon from the position of the observer in any single day. the Sun, the Moon, a planet, or a star) and the visible horizon. Celestial navigation is performed without using satellite navigation or other similar modern electronic or digital positioning means.Ĭelestial navigation uses "sights", or timed angular measurements, taken typically between a celestial body (e.g. 2000 Pub.A diagram of a typical nautical sextant, a tool used in celestial navigation to measure the angle between two objects viewed by means of its optical sightĬelestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space or on the surface of the Earth without relying solely on estimated positional calculations, commonly known as " dead reckoning". He currently resides in Milford, Connecticut. He is also, frequent contributor to Cruising World magazine. About the Author: Hewitt Schlereth is an accomplished sailor who has written several books on navigation a including Commonsense Coastal Navigation and Latitude and Longitude by Noon Sight. The reader is taken carefully through several examples and situational illustrations, making this a most effective self-teaching guide. Schlereth demonstrates how to take sights by the sun, moon a stars and planets, discussing the advantages and disadvantages of each method. ![]() ![]() The basic process is simple: take, sight with sextant, establish, secondary reference or benchmark sight, compare the two sights and plot the result of the comparison on a chart. In this easy-to-use guide, Hewitt Schlereth explains clearly and concisely how to navigate any stretch of sea using only a hand-held sextant, watch, plotting sheet and a copy of the Nautical Almanac. And despite the proliferation of electronic navigational devices, celestial navigation remains an essential tool for those who do not wish to be caught short when modern technology fails. ![]() By Hewitt Schlereth, Practical considerations aside, there is something soul-satisfying about looking to the sky to plot one's course. ![]()
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