Search results
Results from the WOW.Com Content Network
In celestial navigation, lunar distance, also called a lunar, is the angular distance between the Moon and another celestial body. The lunar distances method uses this angle and a nautical almanac to calculate Greenwich time if so desired, or by extension any other time. That calculated time can be used in solving a spherical triangle.
In contrast, the Lunar distance (LD or ), or Earth–Moon characteristic distance, is a unit of measure in astronomy. More technically, it is the semi-major axis of the geocentric lunar orbit . The lunar distance is on average approximately 385,000 km (239,000 mi), or 1.28 light-seconds ; this is roughly 30 times Earth's diameter or 9.5 times ...
Chart of the far side of the moon with lines of longitude and latitude. The selenographic coordinate system is used to refer to locations on the surface of Earth 's moon . Any position on the lunar surface can be referenced by specifying two numerical values, which are comparable to the latitude and longitude of Earth.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
The lunar distance is the angle between a suitable star and the Moon. The dotted lines show the distances between Aldebaran and the Moon, 5 hours apart. Moon not to scale. "Lunars" or lunar distances were an early proposal for the calculation of longitude, having been first made practical by Regiomontanus in his 1474 Ephemerides Astronomicae.
A scroll in the lower left panel of the map is inscribed with instructions on how to use the map and a lunar distance measurement to calculate longitude: it states that by observing the edge of the Moon's disc in relation to a known star, or a lunar eclipse, it is possible to calculate longitude at the point of observation by calculating local ...
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 sight. Celestial 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 ...
Mechanical boxed Marine Chronometer used on Queen Victoria's royal yacht, made about 1865 Omega 4.19 MHz (4 194 304 = 2 22 high frequency quartz resonator) Ships Marine Chronometer giving an autonomous accuracy of less than ± 5 seconds per year, French Navy issued,1980