On any given (sidereal) day/night, a celestial object will appear to drift across, or transit, the observer's upper meridian as Earth rotates, since the meridian is fixed to the local horizon.
Another way, the meridian is divided into the local meridian, the semicircle that contains the observer's zenith and both celestial poles, and the opposite semicircle, which contains the nadir and both poles. The observer's upper meridian passes through the zenith while the lower meridian passes through the nadir. In the horizontal coordinate system, the observer's meridian is divided into halves terminated by the horizon's north and south points.
There are several ways to divide the meridian into semicircles. The intersection of this plane with Earth's surface is the geographical meridian, and the intersection of the plane with the celestial sphere is the celestial meridian for that location and time. For a location not at a geographical pole, there is a unique meridian plane in this axial-pencil through that location.
Meridians, celestial and geographical, are determined by the pencil of planes passing through the Earth's rotation axis. Consequently, it contains also the north and south points on the horizon, and it is perpendicular to the celestial equator and horizon. In astronomy, the meridian is the great circle passing through the celestial poles, as well as the zenith and nadir of an observer's location. An observer's upper meridian, a semicircle, passes through their zenith and the north and south points of their horizon the observer's local meridian is the semicircle that contains their zenith and both celestial poles. Send us feedback.The meridian on the celestial sphere. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'meridian.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. 2019 There’s also a glow-in-the-dark cove and an ASMR tunnel for slime’s visual and auditory qualities, further ballyhooing the restful and spine-tingly autonomous sensory meridian response that has exploded in no-talking videos on YouTube. , 9 June 2019 The Voice is here to help you through the holidays with this exclusive video of Kelly Clarkson and John Legend trying out some ASMR (autonomous sensory meridian response) tactics. 2019 The baseline runs west to the Pacific and east to the Snake River, while the meridian runs north to Puget Sound and south to the California border. 2019 There’s also a glow-in-the-dark cove and an ASMR tunnel for slime’s visual and auditory qualities, further ballyhooing the restful and spine-tingly autonomous sensory meridian response that has exploded in no-talking videos on YouTube.ī, 25 Oct. 2012 Another landed on the dirt meridian that divided the lanes. Geoff Gaherty, Scientific American, 30 Nov. Clair, Men's Health, There is also this simple calculator via Sky & Telescope magazine, which will give you the approximate times the Red Spot transits Jupiter’s central meridian for any date. Recent Examples on the Web Named after the 135° East meridian that crosses Akashi City in the Hyogo prefecture of Japan, 135 is an east-meets-west spirit that’s totally unique.Įlizabeth Brownfield, Forbes, 11 June 2022 And how the ground on which Clint Eastwood and others shot was by the Mediterranean, not beneath the American blood meridian.