Celestial navigation Celestial navigation Celestial navigation, also known as astronavigation, is the ancient and modern practice of position fixing that enables a navigator to transition through a space without having to rely on estimated calculations, or dead reckoning, to know their position. Celestial navigation uses "sights", or angular measurements taken between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. The Sun is most commonly used, but navigators can also use the Moon, a planet, Polaris, or one of 57 other navigational stars whose coordinates are tabulated in the nautical almanac and air almanacs.
Parent body Parent body In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites. The easiest way to correlate a meteorite with a parent body is, when the parent body still exists. This is the case for Lunar and Martian meteorites. Samples from Lunar meteorites can be compared with samples from the Apollo program. Martian meteorites can be compared to analysis carried out by rovers (e.g. Curiosity). Meteorites can also be compared to spectral classes of asteroids. In order to identify the parent body of a class of meteorites, scientists compare their albedo