All Sources -
Updated Media sources (1) About encyclopedia.com content Print Topic
celestial sphere Imaginary sphere of infinite radius used to define the positions of celestial bodies as seen from Earth, the centre of the sphere. The sphere rotates, once in 24 hours, about a line that is an extension of the Earth's axis. The position of a celestial body is the point at which a radial line through it meets the surface of the sphere. The position is defined in terms of coordinates, such as declination and right ascension or altitude and azimuth, which refer to great circles on the sphere, such as the celestial equator or the ecliptic.
More From encyclopedia.com
Sidereal Time , sidereal period Orbital period of a planet or other celestial body with respect to a background star. It is the true orbital period. Sidereal time is… Gaia Hypothesis , The Gaia (pronounced guy-ah) hypothesis is the idea that Earth is a living organism and can regulate its own environment. This idea argues that Earth… Magnetic Field , Earth acts as though it were a huge dipole magnet with the positive and negative poles near the North and South Poles. This does not mean that Earth… Equator , equator •cater, crater, creator, curator, data, debater, delator, dumbwaiter, equator, freighter, frustrater, gaiter, grater, gyrator, hater, later,… azimuth , az·i·muth / ˈazəmə[unvoicedth]/ • n. the direction of a celestial object from the observer, expressed as the angular distance from the north or south… Historical Geology , CONCEPT Geologists are concerned primarily with two subjects: Earth's physical features and the study of the planet's history. These two principal br…
You Might Also Like