Right Ascension, on the other hand, is measured in hours instead of degrees, for historical reasons. Since the Earth is a sphere, 180 E is equal to 180 W. Longitude starts at 0 degrees at the ~ and goes to 180 degree East or 180 degrees West. UT0 is uncorrected UT1 is corrected for the Chandler wobble UT2 is corrected both for the Chandler wobble and for seasonal changes in Earth's rotation rate. It is the same as Greenwich mean time, counted from 0 hours beginning at Greenwich mean midnight. Universal time (UT), the international time standard common to every place in the world, it nominally reflects the mean solar time along the earth's ~ (renumbered to equate to civil time). Longitude: a coordinate system that describes a position on the Earth's surface east or west of an imaginary line known as the ~, which passes through the town of Greenwich, England. The zero point, or " ~", for ecliptic longitude is one of the two points where the ecliptic intersects the plane of the Earth's equator. Any meridian in any coordinate system used as an origin for measurement of longitude.Ĭarrington selected the meridian that passed through the ascending node of the sun's equator at 1200 UTC on 1 January 1854 as the original ~. The meridian of Greenwich, England, is almost universally used for this purpose. The meridian of longitude 0 degrees, used as the origin for measurement of longitude. So we must be somewhere on or just west of this12,500 mile-long semi- circular imaginary line (the 12,500 mile-long semi-circle that completes the circle on the other side of the Earth is the ~). Somewhere just west of the International Date line, where one will first see the sun rise in the year 2000. Planetary co-ordinate systems are defined relative to their mean axis of rotation and various definitions of longitude depending on the body. The ~ is the meridian at which longitude is defined to be 0?.The ~ and the opposite 180th meridian, which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern Hemisphere and Western Hemispheres. A wedge-shaped piece of glass that breaks white light into its constituent colors. It is taken to be the dividing line between the east and west hemispheres, 0 degrees longitude. The meridian on Earth's surface which passes through Greenwich Observatory. Primeval Atmosphere - The original atmosphere of a planet. The zero point of longitude occurs where the ~ intersects the Earth's equator ~ - The circle on the Earth's surface that runs from pole to pole through Greenwich, England. It divides the sky into the eastern and western halves, and is reference point from where hour angle is measured. The meridian passing through the north and south points on the horizon and the zenith. Prism - A piece of glass that breaks white light into it's basic colors, it is wedge shaped. ~ - The line of longitude that runs through Greenwich, England. Prograde The apparent eastward motion of a planet with respect to the stars. ~ The polar great semi-circle adopted as the reference direction for measurement of longitude. The motion of the stars relative to each other, caused by their actual motion in different directions at different speeds through space. The line of longitude that passes through Greenwich, England, and which is the zero line for expressing longitude on Earth's surface. Runs through Greenwich England by current international agreement (1884). Special Meridian that defines Zero Longitude.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |